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mineral groups Flashcards

1
Q

Minerals under carbonates (CALCITE GROUP)

A
  1. calcite CaCo3
  2. magnesite MgCo3
  3. siderite FeCo3
  4. Rhodocrosite MnCo3
  5. smithsonite ZnCo3
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2
Q

Minerals under carbonates (ARAGONITE GROUP)

A
  1. aragonite CaCo3
  2. Witherite baco3
  3. strontianite Srco3
  4. cerussite pbco3
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3
Q

Minerals under carbonates (DOLOMITE GROUP)

A
  1. dolomite-ankerite (ca(fe mg mn)(co3)2)
  2. malachite cu2co3(oh)2)
    3.azurite cu3)co3)2(oh)2)
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4
Q

SULFATES

A
  1. Barite Baso4
  2. celestite srso4
  3. anglesite pbso4
    4.anhydrite caso4
  4. gypsum caso4 2h2o
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5
Q

TUNGSTATE

A
  1. sheelite cawo4
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6
Q

PHOSPHATES

A
  1. apatite ca5(po4)3(F,cl,oh))
  2. amblygonite (LiAl (PO4)(F,OH))
  3. turquoise (CuAl6)(PO4)4(OH)8 4H2O)
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7
Q

enumerate:
CALCITE

Form
cleavage
hardness
SG
remarks

A

hexagonal
rhombohohedral perfect; angle= 74*55’
3
2.71
Distinguished from dolomite by the fact that coarse fragments of calcite effervesce freely in cold dilute HCl, and distinguished from aragonite by lower specific gravity and rhombohedral cleavage.

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8
Q

primary mineral in some igneous rocks such as carbonatites and nepheline syenite. common mineral in hydrothermal veins associated with sulfide ores.

A

calcite

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9
Q

enumerate:
MAGNESITE

Form
cleavage
hardness
SG
remarks

A

rhombohedral crystals
Rhombohedral perfect
3.5 - 5
3.0 - 3.2
The white massive variety resembles chert and is distinguished from it by a lower degree of hardness. Cleavable varieties are distinguished from dolomite by higher specific gravity. Magnesite, almost nonreactive in cold HCl, dissolves with effervescence in hot HCl.

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10
Q

enumerate:
SIDERITE

Form
cleavage
hardness
SG
remarks

A

rhombohedral crystaL
Rhombohedral perfect
3.5 - 4
3.96 (for pure)
Soluble in powdered form in cold HCI or as fragments in hot HCI with effervescence. Distinguished from sphalerite by its rhombohedral cleavage.

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11
Q

occurs as clay ironstone, with admixed clay minerals, in concretions with concentric layers and found in shales and coal measures as blackband ore. a common constituent of sedimentary Precambrian iron-formations, in association with chert and magnetite.

A

SIDERITE

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12
Q

enumerate:
Rhodocrosite

Form
cleavage
hardness
SG
remarks

A

rhombohedral crystals
Rhombohedral perfect.
3.5 - 4
3.5 - 3.7
Its hardness (4) distinguishes it from rhodonite, which has a hardness of 6. Soluble in hot HCI with effervescence.

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13
Q

enumerate:
Smithsonite (ZnCO3)

Form
cleavage
hardness
SG
remarks

A

reniform, botryoidal, or stalactitic
Rhombohedral perfect
4 - 4.5
4.30 - 4.45
Effervesces in powdered form and in hot HCI
distinguished from other carbonates by its hardness of 4 and high specific gravity.

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14
Q

enumerate:
Aragonite (CaCO3)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic crystals
Pinacoidal distinct, prismatic poor
3.5 - 4
2.95
Effervesces in cold dilute HCI. Cleavage fragments of columnar calcite are terminated by rhombohedral cleavage transecting the columnar crystals, whereas columnar aragonite has cleavage parallel to elongation. Distinguished from witherite and strontianite by lower specific gravity and lack of distinctive flame coloration.

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15
Q

Deposited from hot springs, and associated with gypsum As fibrous crusts on serpentine and in amygdaloidal cavities in basalt. In metamorphic assemblages of the blueschist facies, as a result of crystallization at high pressure but relatively low temperature. The pearly layer of many shells and the pearl itself

A

Aragonite

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16
Q

enumerate:
Witherite (BaCO3)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic, with crystals always twinned on {110} forming pseudohexagonal dipyramids by the intergrowth of three individuals
Pinacoidal distinct, prismatic poor
3.5
4.3
associated with galena.
Soluble in cold HCl with effervescence, and gives a yellowish-green flame test. Its high specific gravity is characteristic, and it is distinguished barite by its effervescence in acid.

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17
Q

enumerate:
Strontianite (SrCO3)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic,
Prismatic good.
3.5 - 4
3.7
Occurs in low-temperature hydrothermal veins and deposits associated with barite, celestite, and calcite.
Dissolves with effervescence in dilute HCl, and gives a crimson flame test (for Sr).
Distinguished from celestite by poorer cleavage and effervescence in acid.

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18
Q

enumerate:
Cerussite (PbCO3)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic
reticulated groups of plates crossing each other at 60° angles
Prismatic
3 - 3.5
6.65
Recognized by its high specific gravity (very high for a nonmetallic mineral), white color, and adamantine luster.

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19
Q

enumerate:
Dolomite Group

Form
cleavage
hardness
SG
remarks

A

rhombohedra,
known as “saddle-shaped” crystals
Ankerite: Generally not found in well-formed crystals. When in crystals, they resemble those of dolomite.
Rhombohedral perfect
3.5 - 4
2.85 (dolomite), 3.1 (ankerite)
Ankerite: a common carbonate in Precambrian iron-formations in association with chert, magnetite, and hematite.
In cold, dilute HCl large fragments of dolomite and ankerite are slowly attacked; they become soluble, with effervescence, only in hot HCl.

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20
Q

enumerate:
Malachite (Cu2CO3(OH)2)

Form
cleavage
hardness
SG
remarks

A

monoclinic, prismatic crystals but seldom distinct.
Pinacoidal perfect but rarely seen
3.5 - 4
3.9 - 4.03
Soluble in cold dilute HCI with effervescence, giving a green solution.

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21
Q

enumerate:
Azurite (Cu3(CO3)2(OH)2)

Form
cleavage
hardness
SG
remarks

A

Monoclinic
Prismatic perfect, pinacoidal fair
3.5 - 4
3.77
Characterized chiefly by its effervescence in cold dilute HCI,

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22
Q

enumerate:
SULFATES
Barite (BaSO4)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic crystals usually tabular on {001}.
Pinacoidal perfect, prismatic less perfect
3 - 3.5
4.5.
Gives a yellowish-green flame test.

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23
Q

enumerate:
SULFATES
Celestite (SrSO4)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic
001} or prismatic parallel to the a or b axis.
3 - 3.5
3.95 - 3.97
Common in lead veins with galena.
Closely resembles barite but is differentiated by lower specific gravity and a crimson flame test (for Sr)

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24
Q

enumerate:
SULFATES
Anglesite (PbSO4)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic crystals
Basal food, prismatic imperfect. Fracture conchoidal
3.0
6.2 - 6.4
Associated with galena, cerussite, sphalerite, smithsonite, hemimorphite, and iron oxides
its common association with galena.

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25
Q

enumerate:
SULFATES
Anhydrite (CaSO4)

Form
cleavage
hardness
SG
remarks

A

Orthorhombic
Three pinacoidal cleavages
3 - 3.5
2.89 - 2.98
Occurs in beds associated with salt deposits in the cap rock of salt domes, and in limestones. Also in amygdaloidal cavities in basalts.
Characterized by its three cleavages at right angles. It is distinguished from calcite by its higher specific gravity and from gypsum by its greater hardness.

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26
Q

enumerate:
SULFATES
Gypsum (CaSO4·2H2O)

Form
cleavage
hardness
SG
remarks

A

Monoclinic crystals of simple habit. Commonly tabular on {010}; diamond-shaped with beveled edges
Pinacoidal {010} perfect, yielding thin folia; {100} with conchoidal surface; {110} with fibrous fracture.
2
2.32
Characterized by its softness and its three unequal cleavages.

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27
Q

enumerate:
SULFATES
Scheelite (CaWO4)

Form
cleavage
hardness
SG
remarks

A

Tetragonal dipyramidal crystals of which the dipyramid {112} closely resembles the octahedron in angles
Prismatic
4.5 - 5
5.9 - 6.1
will fluoresce with bluish-white color in short ultraviolet radiation.
Found in granite pegmatites, contact metamorphic deposits, and high-temperature hydrothermal veins associated with granitic rocks. Common associations are cassiterite, topaz, fluorite, apatite, and molybdenite.

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28
Q

enumerate:
PHOSPHATES
Apatite (Ca5(PO4)3(F,Cl,OH))

Form
cleavage
hardness
SG
remarks

A

Hexagonal
Basal poor
5 (can be scratched by a knife)
3.15 - 3.20
distinguished from beryl by inferior hardness and from quartz by color and hardness. Massive, granular varieties may resemble diopside, but apatite is of inferior hardness.

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29
Q

massive, cryptocrystalline type)

A

collophane

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30
Q

he variety collophane (a massive, cryptocrystalline type) constitutes the bulk of

A

phosphorite or phosphate rock.

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31
Q

enumerate:
PHOSPHATES
Amblygonite (LiAl(PO4)(F,OH))

Form
cleavage
hardness
SG
remarks

A

Triclinic
{100} perfect
6
3.0 - 3.1
Found mainly in Li-bearing granite pegmatites in association with spodumene, tourmaline, lepidolite, and apatite.
Resembles albite, However, different cleavage angles and the less perfect cleavage of amblygonite, as well as the higher specific gravity, distinguish it from albite. A flame test gives a diagnostic red coloring for Li.

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32
Q

enumerate:
PHOSPHATES
Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Form
cleavage
hardness
SG
remarks

A

triclinic crystals
Basal perfect
6
2.6 - 2.8
found in small veins and stringers traversing more or less decomposed volcanic rocks in arid regions.
harder than chrysocolla, the only common mineral that it resembles.

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33
Q

minerals under OXIDES

A
  1. CUPRITE (Cu2O)
  2. CORUNDUM (Al2O3)
  3. HEMATITE (Fe2O3)
  4. ILMENITE (FeTiO3)
  5. RUTILE (TiO2)
  6. PYROLUSITE (MnO2)
  7. CASSITERITE (SnO2)
  8. URANINITE (UO2)
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34
Q

OXIDES: SPINEL GROUP

A
  1. SPINEL (MgAl2O4)
  2. MAGNETITE (Fe3O4)
  3. CHROMITE (FeCr2O4)
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35
Q

HYDROXIDES MINERALS

A
  1. BRUCITE (Mg(OH)2)
  2. MANGANITE (MnO(OH))
  3. ROMANECHITE (Ba,H2O)2(Mn4+,Mn3+)5O10
  4. GOETHITE (FeO(OH))
  5. LIMONITE FeO(OH)·nH2O
  6. BAUXITE
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36
Q

HALIDES

A
  1. HALITE (NaCl)
  2. SYLVITE (KCl)
  3. FLUORITE (CaF2)
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37
Q

enumerate:
PHOSPHATES
CUPRITE (Cu2O)

Form
cleavage
hardness
SG
remarks

A

isometric crystals that show cube,
NO CLEAVAGE(?)
Hardness
3 1/2 -4
Specific Gravity
6.1
. Streak brownish red.
Found, as a supergene mineral, in the oxidized portions of copper deposits
associated with limonite and secondary copper minerals such as native copper, malachite, azurite, and chrysocolla.
distinguished by its red color, isometric crystal form, high luster, brown, streak, and association with limonite.

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38
Q

ruby red in transparent crystals CUPRITE

A

ruby copper.”

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39
Q

enumerate:
PHOSPHATES
CORUNDUM (Al2O3)

Form
cleavage
hardness
SG
remarks

A

Prismatic or tabular hexagonal crystals are common
Cleavage
Only parting on {0001} and {10\bar1 1}
Hardness 9
Specific Gravity
4.02
present in SiO2– poor igneous rocks such as syenites and nepheline syenites. Occurs also as rolled pebbles in detrital soil and stream sands.

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40
Q

gem corundum of any other color. Luster adamantine to vitreous.

A

sapphire

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41
Q

enumerate:
PHOSPHATES
HEMATITE (Fe2O3)

Form
cleavage
hardness
SG
remarks

A

hexagonal
also be micaceous and foliated and referred to as specular hematite.
Parting on { 10bar1 1} and {0001}
Hardness
5 1/2 - 6 1/2 (for crystals)
Specific Gravity
5.26 (for crystals)
accessory constituent of many rock types and the most abundant iron ore mineral in Precambrian banded iron-formations.
Distinguished mainly by its characteristic red streak, reddish-brown to black color,

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42
Q

Red earthy variety known as
platy and metallic variety known as hematite

A

red orcher
specularite

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43
Q

enumerate:
PHOSPHATES
ILMENITE (FeTiO3)
Form
cleavage
hardness
SG
remarks

A

massive and compact.
Hardness
5 1/2 - 6
Specific Gravity
4.7
occur as large masses in gabbros, diorites, and anorthosites, commonly associated with magnetite. As a constituent of black sand, it is associated with magnetite, rutile, and zircon.
Distinguished from hematite by its streak and from magnetite by its lack of strong magnetism.

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44
Q

enumerate:
PHOSPHATES
RUTILE (TiO2)
Form
cleavage
hardness
SG
remarks

A

tetragonal, prismatic crystals with dipyramid terminations
Cleavage
Prismatic {110} distinct
Hardness
6-6 1/2
Specific Gravity
4.18-4.25
Characterized by its adamantine luster and red color. It has a lower specific gravity than cassiterite.
Found in granite, granite pegmatite, mica schist, gneiss, metamorphic limestone, and dolomite.

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45
Q

enumerate:
PHOSPHATES
PYROLUSITE (MnO2)
Form
cleavage
hardness
SG
remarks

A

radiating fibers or columns
pseudomorphous after manganite.
Cleavage
Prismatic {110} perfect; fracture splintery.
Hardness
1– 2 (often soils the fingers); for coarsely crystalline polianite the hardness is 6 –6 1/2
Specific Gravity
4.75
found as nodular deposits in bogs, on lake bottoms, and on the floors of oceans.
black streak and low degree of hardness.

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46
Q

enumerate:
PHOSPHATES
CASSITERITE (SnO2)
Form
cleavage
hardness
SG
remarks

A

two tetragonal prisms and dipyramids.
also in reniform shapes with radiating fibrous appearance, known as wood tin.
Prismatic {010} imperfect
6-7
6.8-7.1 (unusually high for a nonmetallic mineral)
ound in high-temperature hydrothermal veins in or near granitic rocks.
Vein associations may include tourmaline, topaz, fluorite, apatite, molybdenite, and arsenopyrite

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47
Q

cassiterite also occur as rolled pebbles in placer deposits, know as

A

stream tin.

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48
Q

enumerate:
PHOSPHATES
URANINITE (UO2)
Form
cleavage
hardness
SG
remarks

A

Most commonly as massive or botryoidal forms with a banded structure, known as pitchblende.
Hardness
5 1/2
Specific Gravity
6.5 – 9, for pitchblende. Crystals show G 7.5 – 9.7.
Characterized chiefly by its pitchy luster, high specific gravity, color, streak, and strong radioactivity (as detected by a Geiger counter or scintillation counter).
primary constituent of granitic rocks and pegmatites, and in high-temperature hydrothermal veins associated with cassiterite, chalcopyrite, and arsenopyrite. Also in association, at low temperatures, with secondary uranium minerals.

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49
Q

enumerate:
SPINEL GROUP
SPINEL (MgAl2O4)
Form
cleavage
hardness
SG
remarks

A

Isometric.
Commonly in octahedral crystals or in twinned octahedrons (spinel twins)
Hardness
8
Specific Gravity
3.5-4.1
high-temperature mineral occurring in contact-metamorphosed limestones and metamorphic rocks poor in SiO2. Metamorphic assemblages may contain phlogopite, pyrrhotite, and graphite
found as rolled pebbles in stream sands.
Iron-rich spinel is distinguished from magnetite by being nonmagnetic and having a white streak.

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50
Q

enumerate:
SPINEL GROUP
MAGNETITE (Fe3O4)
Form
cleavage
hardness
SG
remarks

A

Isometric. Frequently in octahedral crystals
Cleavage
None. Octahedral parting in some specimens.
Hardness
6
natural magnet, known as lodestone
titaniferous
major constituent of Precambrian banded iron-formations
association with chert and hematite. Also found in black sands along seashores. Often closely intergrown with corundum, forming emery.

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51
Q

enumerate:
SPINEL GROUP
CHROMITE (FeCr2O4)
Form
cleavage
hardness
SG
remarks

A

Isometric, with octahedral habit, but crystals rare
Hardness
5 1/2
Specific Gravity
4.6
common constituent of peridotites, of other ultrabasic rocks, and of serpentine derived from them. Associated with olivine, serpentine, and corundum.
Lack of magnetism and brown streak distinguishes it from magnetite. Association with olivine and serpentine is highly characteristic.

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52
Q

enumerate:
HYDROXIDES
BRUCITE (Mg(OH)2)
Form
cleavage
hardness
SG
remarks

A

foliated, massive. When in crystals, they are hexagonal, usually tabular on {0001}
Cleavage
Basal {0001} perfect. Folia flexible but not elastic. Sectile.
Hardness
2 1/2
Specific Gravity
2.39
association with serpentine dolomite, magnetite, and chromite. As a reaction product of Mg-silicates, especially serpentine. Recognized by its foliated nature, light color, and pearly luster on cleavage faces. Distinguished from talc by being considerably harder, and from mica by being inelastic.

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53
Q

enumerate:
HYDROXIDES
MANGANITE (MnO(OH))
Form
cleavage
hardness
SG
remarks

A

Monoclinic crystals that are prismatic parallel to the c axis and vertically striated.
Pinacoidal {010} perfect, {110} and {001} good
4
4.3
low-temperature hydrothermal veins associated with barite, siderite, and calcite. It commonly alters to pyrolusite.
Hardness (4) and brown streak distinguish it from pyrolusite.

54
Q

enumerate:
HYDROXIDES
ROMANECHITE (Ba,H2O)2(Mn4+,Mn3+)5O10
Form
cleavage
hardness
SG
remarks

A

Massive, botryoidal, stalactitic; appears amorphous..
Hardness
5-6
Specific Gravity
3.7-4.7
product of secondary alteration of original Mn-carbonates, Mn-silicates
ssociation with pyrolusite in manganese ore deposits, in nodular deposits in bogs, and on lake bottoms and on see and ocean floors.
Distinguished from other manganese oxides by its greater hardness and botryoidal form and from limonite by its black streak.

55
Q

Many of the hard botryoidal masses formerly called mixtures of manganese oxides of which romanechite is a major constituent.

A

psilomelane

56
Q

enumerate:
HYDROXIDES
GOETHITE (FeO(OH))
Form
cleavage
hardness
SG
remarks

A

prismatic (orthorhombic), vertically striated crystals. Generally massive, reniform, stalactitic, and in radiating fibrous aggregation. Foliated. So-called bog ore is generally loose and porous.
Cleavage
Pinacoidal {010} perfect
Hardness
5 - 5 1/2
Specific Gravity
4.37, but may be as low as 3.3 for impure material
resulting from oxidation and weathering of iron-bearing minerals. It is a widespread deposit in bogs and around springs. It constitutes the gossan or “iron hat” over metalliferous vein deposits.
Distinguished from colloform hematite and romanechite by color and streak.

57
Q

very fine-grained to amorphous mixtures of brown ferric hydroxides whose real identities are unknown has variable compositions (and variable chemical and physical properties) and consists of a mixture of several iron hydroxides (commonly with goethite a major constituent) or of a mixture of several minerals such as hematite, goethite, or lepidochrocite, with or without additional absorbed water.

A

LIMONITE FeO(OH)·nH2O

58
Q

enumerate:
HYDROXIDES
BAUXITE
Form
cleavage
hardness
SG
remarks

A

The term bauxite is a rock term, not the name of a mineral species, because bauxite consists of a very fine-grained intergrowth of three aluminum hydroxides, diaspore, gibbsite, and boehmite. Bauxite is the major ore of aluminum.

A mixture. Pisolitic, in round concretionary grains. Also massive, earthy, claylike.
Hardness
1-3
Specific Gravity
2-2.55
supergene origin, commonly produced under subtropical to tropical conditions by prolonged weathering and leaching of silica from aluminum-bearing rocks. Laterite, formed in the tropics, is a soil consisting mainly of hydrous aluminum and ferric oxides.

59
Q

enumerate:
HALIDES
HALITE (NaCl)
Form
cleavage
hardness
SG
remarks

A

Isometric, with cubic habit
When in crystals or granular crystalline masses showing cubic cleavage, known as rock salt. Also massive, granular to compact.
Cleavage
Cubic {001} perfect
2 1/2
2.16
aluable deposits are also found in intrusive masses known as salt domes, which have their roots in thick, bedded deposits.
Characterized by its cubic cleavage and taste, and distinguished from sylvite by a less bitter taste and yellow flame color,* caused by the presence of sodium.

60
Q

enumerate:
HALIDES
SYLVITE (KCl)
Form
cleavage
hardness
SG
remarks

A

Isometric crystals with cube and octahedron frequently in combination. Usually in granular crystalline masses with good cubic cleavage; also compact.
Cubic {001} perfect
2
1.99
red caused by impurities. Transparent when pure.
distinguished from halite by its bitter taste and sectility. On scratching a smooth surface, a knife produces a powder with halite, but very little powder with sylvite.

61
Q

enumerate:
HALIDES
FLUORITE (CaF2)
Form
cleavage
hardness
SG
remarks

A

Isometric, usually in cubes, and often in penetration twins
Octahedral {111} perfect
4
3.18
show fluorescence under ultraviolet radiation.
hydrothermal veins it may be the chief mineral, or it may be the gangue mineral in metallic ores, especially those of lead and silver. Also common in dolomites and limestones. May be associated with many different minerals, among them calcite, dolomite, gypsum, celestite, barite, quartz, galena, sphalerite, cassiterite, topaz, tourmaline, and, apatite.
cubic crystals and perfect octahedral cleavage
can be scratched by a knife. It is harder than calcite and does not effervesce with cold HCl.

62
Q

what are the elements under native elements

A
  1. Gold (Au)
  2. Silver (Ag)
    Copper (Cu)
  3. Sulfur (S)
  4. Diamond (C)
  5. Graphite (C)
63
Q

minerals under sulfides

A
  1. Chalcocite (Cu2S)
  2. Bornite (Cu5FeS4)
  3. Galena (PbS)
  4. Sphalerite (ZnS)
  5. Chalcopyrite (CuFeS2)
  6. Pyrrhotite (Fe(1-x)S) x = 0 - 0.2
  7. Pentlandite (Fe,Ni)9S8
  8. Covellite (CuS)
  9. Realgar (As4S4)
  10. Orpiment (As2S3)
  11. Stibnite (Sb2S3)
  12. Pyrite (FeS2)
  13. Marcasite (FeS2)
  14. Molybdenite (MoS2)
  15. Arsenopyrite (FeAsS)
  16. Enargite (Cu3AsS4)
64
Q

enumerate:
NATIVE ELEMENTS
Gold (Au)
Form
cleavage
hardness
SG
remarks

A

Isometric, with crystals commonly octahedral. Also in rounded or flattened grains, “nuggets.”
Hardness 2.5 - 3; fracture hackly. Very malleable and sectile.
Specific Gravity 19.3 when pure. The presence of other metals (usually silver) decreases the specific gravity,which may be as low as 15.
Various shades of yellow depending on the purity, becoming paler with increasing silver content.
chief sources of gold are (1) hydrothermal gold – quartz veins in which it is commonly so
fine-grained that its presence
(2) placer deposits, and their
lithified equivalents known as conglomerates, in which the gold occurs as fine detrital grains and
nuggets.
characterized by its
color, malleability, and sectility. In small grains it can be easily confused with pyrite and
chalcopyrite, hence the common designation fool’s gold for these minerals. Pyrite has a much
greater hardness, and chalcopyrite is brittle instead of malleable and sectile.

65
Q

enumerate:
NATIVE ELEMENTS
Silver (Ag)
Form
cleavage
hardness
SG
remarks

A

Isometric crystals are commonly malformed and in branching,
Hardness 2.5 - 3. Fracture hackly. Malleable and ductile
Specific Gravity 10.5 when pure, 10 – 12 when impure.
precipitated from primary hydrothermal solutions.
distributed, in smaller amounts, in the oxidized zones of ore deposits.
Native silver is distinguished by its malleability, color on the fresh surface, and high
specific gravity.

66
Q

enumerate:
NATIVE ELEMENTS
3. Copper (Cu)
Form
cleavage
hardness
SG
remarks

A

Isometric crystals with tetrahexahedral, cube, dodecahedral, and octahedral faces are common.
Hardness 2.5 - 3. Highly ductile and malleable. Fracture hackly.
Specific Gravity 8.9
associated with
cuprite, malachite, and azurite.
Primary deposits of native copper are associated with basaltic
lavas, where copper was deposited through the reaction of hydrothermal solutions with iron oxide
minerals.

Remarks Native copper is recognized by its red color on fresh surfaces, hackly fracture, high specific

gravity, and malleability.

67
Q

enumerate:
NATIVE ELEMENTS
Sulfur (S)
Form
cleavage
hardness
SG
remarks

A

Orthorhombic crystals with pyramidal habit, commonly with two dipyramids, prism {011},
None. Fracture conchoidal to uneven. Brittle.
1.5 - 2.5
2.05 - 2.09
most common in Tertiary sedimentary rocks associated with anhydrite, gypsum, and
limestone. Other associations include celestite, gypsum, calcite, and aragonite.

68
Q

enumerate:
NATIVE ELEMENTS
Diamond (C)
Form
cleavage
hardness
SG
remarks

A

Isometric crystals with octahedral form most common; cubes and dodecahedrons may occur as well. Bort, a variety of diamond, has rounded forms and a rough exterior resulting from a radial or cryptocrystalline aggregate.
Octahedral {111} perfect
3.51
Carbonado or carbon is a black or grayish-black bort. It is noncleavable, opaque, and less brittle
than crystals.
occurrence of diamonds is in altered peridotite called kimberlite, as intrusive bodies
that are commonly circular with a pipelike shape and referred to as “diamond pipes.” Kimberlite
consists of rounded and corroded phenocrysts of olivine, phlogopite, ilmenite, and pyrope in a
fine-grained matrix of olivine, phlogopite, serpentine, spinels, calcite, and/or dolomite. A large
percentage of diamonds are recovered from alluvial deposits (known as placers), where they
accumulate because of their inert nature, great hardness, and fairly high specific gravity. The size (and weight) of diamonds, and other gemstones, is
expressed in carats, where 1 carat = 200 milligrams.

69
Q

enumerate:
NATIVE ELEMENTS
Graphite (C)
Form
cleavage
hardness
SG
remarks

A

Tabular crystals with hexagonal outline and a prominent basal face are quite common. Usually in foliated or scaly masses;
Basal {0001} perfect. Folia flexible but not elastic.
1– 2 (readily marks paper and soils the fingers). Greasy feel.
2.23
metamorphic rocks such as crystalline limestones, schists, and
gneisses. It is also present in hydrothermal veins associated with quartz, orthoclase, tourmaline,
apatite, pyrite, and titanite. It may also occur as an original constituent of some igneous rocks.
distinguished from molybdenite by its black color
(molybdenite has a blue tone), and black streak on porcelain (molydenite has a grayish-black
streak).

70
Q

enumerate:
SULFIDES
Chalcocite (Cu2S)
Form
cleavage
hardness
SG
remarks

A

massive and very fine-grained. If in orthorhombic crystals,
Prismatic {110} poor. Fracture conchoidal
2.5 - 3. Imperfectly sectile
5.5 - 5.8
occurs as a primary mineral in

hydrothermal veins, with bornite, chalcopyrite, enargite, and pyrite. Its most common occurrence
is as a supergene mineral in enriched zones of sulfide deposits, often forming “chalcocite
blankets” at the level of the water table. It is also a constituent of “porphyry copper” deposits,
disseminated throughout porphyrytic granodiorite intrusives.
low degree of hardness, and slight sectility.

71
Q

enumerate:
SULFIDES
Bornite (Cu5FeS4)
Form
cleavage
hardness
SG
remarks

A

Rarely in tetragonal crystals; usually massive.
3
5.06-5.08
Brownish bronze on fresh surface but quickly tarnished to variegated purple and blue (hence
called peacock ore) and finally to almost black on exposure.
associated with other sulfides such as chalcocite, chalcopyrite, covellite, pyrrhotite,
and pyrite in hypogene deposits. It occurs less frequently as a supergene mineral in the upper
enriched parts of copper veins.

72
Q

enumerate:
SULFIDES
Galena (PbS)
Form
cleavage
hardness
SG
remarks

A

Isometric crystals with the most common form the cube,
2.5
7.4 - 7.6
Lead-gray with lead-gray streak. Luster bright metallic. associated with sphalerite, marcasite,
chalcopyrite, cerussite, anglesite, calcite, quartz, barite, and fluorite.
distinguished from stibnite by its cubic cleavage, specific gravity, and darker color.

73
Q

enumerate:
SULFIDES
Sphalerite (ZnS)
Form
cleavage
hardness
SG
remarks

A

Isometric with the tetrahedron, dodecahedron, and cube as common forms.
Dodecahedral {011} perfect but some sphalerite is too fine-grained to show cleavage.
3.5 - 4
3.9 - 4.1
Colorless when pure ZnS and green when nearly so. Commonly yellow, brown to black, darkening
with increase in iron. Also red (ruby zinc). Luster nonmetallic and resinous to submetallic; also
adamantine. Transparent to translucent. Streak white to yellow and brown.
most common ore mineral of zinc, is widely distributed. Its occurrence and mode of

origin are similar to those of galena,
Recognized by its striking resinous luster, perfect cleavage, and hardness (3 – 4).
The dark varieties (black jack)
can be told by the reddish-brown streak, always lighter than that of the massive mineral.

74
Q

enumerate:
SULFIDES
Chalcopyrite (CuFeS2)
Form
cleavage
hardness
SG
remarks

A

Tetragonal, commonly appearing tetrahedral on account of the disphenoid {112}.
3.5 - 4 ; brittle
3.1 - 3.4
Streak greenish black.
low-temperature hydrothermal vein deposits it is found with galena, sphalerite, and dolomite. In
higher-temperature deposits it may occur with pyrrhotite and pentlandite.
Distinguished from pyrite by
being softer than a steel knife and from gold by being brittle. Known as “fool’s gold,” a term also
applied to pyrite.

75
Q

enumerate:
SULFIDES
Pyrrhotite (Fe(1-x)S) x = 0 - 0.2
Form
cleavage
hardness
SG
remarks

A

Hexagonal (for the high-temperature form
4
4.58-4.65
easily attracted to a magnet, but much less magnetic than magnetite.
sulfide ore deposits

commonly associated with pentlandite, chalcopyrite, and other sulfides.
is distinguished from chalcopyrite by its color and magnetism, and from pyrite by color and
hardness. The massive variety may be associated with pentlandite, from which it is distinguished
only with difficulty.

76
Q

enumerate:
SULFIDES
Pentlandite (Fe,Ni)9S8
Form
cleavage
hardness
SG
remarks

A

Isometric, but most commonly massive, in granular aggregates with octahedral parting.
None; octahedral parting on {111}.
3.5 - 4
4.6 - 5.0
Pentlandite closely resembles pyrrhotite, distinguished from pyrrhotite by its octahedral parting and lack of magnetism. The presence of
nickel can be quickly established by a test with dimethylglioxime. (When a little dimethylglioxime
powder is dissolved in some water on a pentlandite specimen, a scarlet coloration forms,
indicating the presence of nickel.)

77
Q

enumerate:
SULFIDES
Covellite (CuS)
Form
cleavage
hardness
SG
remarks

A

Rarely in tabular, hexagonal crystals.
Basal {0001} perfect
1.5 - 2
4.6 - 4.76
commonly found in most copper ore deposits as a supergene
mineral. It is found with other copper minerals, mainly chalcocite, chalcopyrite, bornite, and
enargite, commonly found in most copper ore deposits as a supergene
mineral. It is found with other copper minerals, mainly chalcocite, chalcopyrite, bornite, and
enargite,

78
Q

enumerate:
SULFIDES
Realgar (As4S4)
Form
cleavage
hardness
SG
remarks

A

Monoclinic, but crystals uncommon. Generally coarse- to fine-granular and often earthy and as encrustations.
Pinacoidal good
1.5 - 2;sectile
3.48
hydrothermal veins with orpiment, associated with lead and silver minerals, as well as
with stibnite. It also occurs as a volcanic sublimation product and as a deposit from hot springs.
Distinguished by its red color, orange-red streak, resinous luster, and almost invariable

association with orpiment.

79
Q

enumerate:
SULFIDES
Orpiment (As2S3)
Form
cleavage
hardness
SG
remarks

A

Monoclinic, but crystals rare. Usually in foliated, columnar, or fibrous masses
Pinacoidal {010} perfect. Cleavage laminae flexible but not elastic
1.5 - 2 ; sectile
3.49
associated usually with realgar and formed under similar conditions.
Remarks Characterized by its yellow color, foliated structure, and excellent cleavage. Distinguished from

sulfur by its cleavage and sectility.

80
Q

enumerate:
SULFIDES
Stibnite (Sb2S3)
Form
cleavage
hardness
SG
remarks

A

Orthorhombic. Crystals common.
Pinacoidal {010} perfect, with striations parallel to [100]
2
4.52-4.62
Lead-gray to black. Streak also lead-gray to black.
low-temperature hydrothermal veins or replacement deposits and in hotsprings deposits.
It is associated with other antimony minerals that have formed as the product of its decomposition,
and with galena, cinnabar, sphalerite, barite, realgar, orpiment, and gold.
bladed habit, perfect cleavage in one direction, lead-gray color, and soft black

streak. It is distinguished from galena by its cleavage, habit, and lower specific gravity.

81
Q

enumerate:
SULFIDES
Pyrite (FeS2))
Form
cleavage
hardness
SG
remarks

A

Isometric. Frequently in crystals. The most common forms are the cube
None. Fracture conchoidal. Brittle.
6-6.5 (unusually hard for a sulfide)
5.02
common and widespread sulfide minerals,
accessory mineral in igneous rocks, and
in contact metamorphic deposits and hydrothermal veins. It is also common in sedimentary rocks,
especially shales and limestones. In vein deposits it is associated with many minerals but most
frequently with chalcopyrite, sphalerite, and galena.
Distinguished from chalcopyrite by its paler color and greater hardness, from gold by its brittleness
and hardness, and from marcasite by its deeper color and crystal form. Pyrite is easily altered to
limonite. Pseudomorphic crystals of limonite after pyrite are common. Pyrite veins are usually
capped by a cellular deposit of limonite, termed gossan.

82
Q

enumerate:
SULFIDES
Marcasite (FeS2)
Form
cleavage
hardness
SG
remarks

A

Orthorhombic. Polymorphous with pyrite. Crystals commonly tabular on {010}; less commonly
prismatic parallel to [001]. Also globular and reniform.
6-6.5
4.89
found in metalliferous veins, frequently with lead and zinc ores. It is less stable than pyrite
(being easily decomposed) and much less common. It is commonly found as a supergene mineral
deposited at low temperatures, at near-surface conditions. It is also found as replacement
deposits in limestone and in concretions in shales.
distinguished from pyrite by its pale yellow color, its crystals, or its fibrous

habit.

83
Q

enumerate:
SULFIDES
Molybdenite (MoS2)
Form
cleavage
hardness
SG
remarks

A

Hexagonal. Crystals in hexagonal plates or short, slightly tapering prisms.
Basal {0001} perfect, with laminae flexible but not elastic.
1-1.5; greasy feel
4.62-4.73.
an accessory mineral in some granites; in pegmatites and aplites. Common in
high-temperature vein deposits associated with cassiterite, scheelite, and fluorite. Also in contact
metamorphic deposits with Ca-silicates, scheelite, and chalcopyrite.
molybdenite resembles graphite, it can be distinguished from it by higher specific gravity
and by a blue tone to its color (graphite has a brown tinge). On glazed poreclain it gives a
greenish streak, graphite a black streak.

84
Q

enumerate:
SULFIDES
Arsenopyrite (FeAsS))
Form
cleavage
hardness
SG
remarks

A

Monoclinic. Crystals are commonly prismatic and elongated along the c axis and less commonly
along the b.
Prismatic {101} poor
5.5 - 6
6.07
the most common mineral containing arsenic.
occurs with tin and tungsten ores
in high-temperature hydrothermal deposits. Also associated with silver and copper ores, galena,
sphalerite, pyrite, and chalcopyrite. Also found as an accessory in pegmatites, in contact
metamorphic deposits, and disseminated in crystalline limestones.
Distinguished from marcasite by its silver-white color. Unambiguous identification may require

some chemical tests for As and S.

85
Q

enumerate:
SULFIDES
Enargite (Cu3AsS4)
Form
cleavage
hardness
SG
remarks

A

Orthorhombic. Crystals elongated parallel to the c axis and vertically striated. Also tabular parallel to {001}. Columnar, bladed, massive.
Prismatic {110} perfect, {100} and {010} distinct
3
4.45
Found in vein and replacement deposits formed at moderate temperatures associated with pyrite, sphalerite, bornite, galena, and chalcocite
Characterized by its color and cleavage. Striated crystals are also diagnostic.

86
Q

(Greek, meaning correct or true) sediments - truly chemical sediments which are products of chemical decomposition

A

Orthochemical

87
Q

(Greek, meaning different) sediments - organisms have caused the precipitation of the major sedimentary mineral components, or the precipitated minerals have undergone substantial movement (and redeposition) after their crystallization

A

Allochemical

88
Q

consist of detrital grains, which form the framework of the rock, and which are joined together by cement. Variable amounts of matrix, which consists of fragmental material substantially smaller than the mean size of the framework grains, may also be present. The texture is a composite of the grain size, grain shapes, sorting, and angularity of the framework grains.

A

Terrigenous sedimentary rocks

89
Q

consists of large clasts (boulders, cobbles, pebbles, and granules) with or without a sandy matrix; conglomerates show pronounced rounding of the clasts whereas breccias contain more angular clasts.

A

Conglomerates and breccias -

90
Q

coarse-grained pyroclastics (volcanic debris) with a grain size over 32 mm

A

Agglomerates or volcanic breccia

91
Q

finer-grained (grain size between 2 and 0.062 mm) and most easily classified by determining the amounts of clastic (framework) grains composed of quartz (and chert), feldspar, and lithic fragments

A

Sandstones

92
Q

when the sandstone matrix constitutes more than 10 volume percent of the rock

A

Wacke

93
Q

mostly dark gray sandstones with abundant matrix

A

Greywacke

94
Q

sandstones made up of chiefly volcanic fragments, volcanic glass, and crystals. Tend to be green because of chlorite.

A

Volcaniclastics

95
Q

with abundant volcanic fragmens the volcanic a glassy groundmass. ppl field of view is 5mm wide

A

lithic arenite

96
Q

most of the feldspars shows alteration along cleavage and twin planes

A

felspathic arenite

97
Q

95% quartz cemented by quartz overgroths bar scale is 0.3 mm crossed nicols

A

quartz arenite

98
Q

general term for sediments composed mainly of silt-sized, (0.062 to 0.004 mm) and clay-sized (<0.004 mm) particles

A

Mudstone

99
Q

haracterized by its fissility (ability to split into thin sheets), generally parallel to bedding

A

Shale

100
Q

with a well-developed cleavage, which may or may not be parallel to the bedding, and is commonly the result of metamorphism

A

Slate

101
Q

calcite recrystallizes easily, and secondary dolomite, replaces the original calcium carbonate; often destroys the texture of the original carbonate

A

Dolomitization Allochemical Carbonate Rocks

102
Q

Orthochem components
a very fine-grained carbonate precipitate that has settled to the bottom of the basin

coarser in grain size than the ooze and tends to be clear or translucent; a pore-filling cement that was precipitated in place

A

Microcrystalline ooze

Sparry calcite cement

103
Q

Allochem components
fragments of weakly consolidated carbonate sediment that have been torn up, transported, and redeposited by currents within the basin of deposition

A

Intraclasts

104
Q

in a size range of 0.1 to 1.0 mm in diameter, are spherical, show radial and concentric structures, and resemble fish roe. They are commonly formed by chemical accretion around nuclei such as shell fragments, pellets, or quartz sand grains

A

Oolites

105
Q

well-rounded, homogeneous aggregates of microcrystalline calcite in a size range of 0.03 to 0.2 mm in diameter; feces of mollusks, worms, and crustaceans

A

Pellets

106
Q

Folk’s Classification of Limestones
consist of a matrix of allochemical constituents and sparry calcite cement

variable percentage of allochemical grains in a microcrystalline matrix

microcrystalline calcite matrix only (micrite)

A

Type 1
Type 2

107
Q

emphasizes the depositional texture; “Were the framework grains (Folk’s allochems) in close contact with each other, that is, were they well packed when they were deposited?”

A

Dunham’s Classification of Limestones

108
Q

consists of more than 10% grains in a microcrystalline ooze (micrite)

A

Wackestone

109
Q

grain-supported limestone with micrite matrix and sparry calcite cement

A

Packstone

110
Q

grain-supported limestone with very little micrite.

A

Grainstone

111
Q

equivalent to biolithite, a limestone made up of organic structures that grew in situ (in place), forming a coherent rock mass during growth

A

Boundstone

112
Q

formed by direct precipitation Examples - evaporites, banded iron formations, travertine

A

Orthochemical sedimentary rocks

113
Q

clasts within carbonate rocks

A

allochems

114
Q

robert fold and robert dunham life

A

1929-2018
1924-1994

115
Q

based on depositional environment and based on allochems

A

dunham
folks

116
Q

mud supported fine grained allochems <2mm

A

mudsupported wackestone

117
Q

grain supported has mud

A

packstone

118
Q

lacks mud and is grain supported

A

grainstone calcite amtrix:sparite

119
Q

matrix supported

A

floatstone

120
Q

supported by >2mm componetnt coarse grained allochemcs >10% grains are >2mm

A

rudstone

121
Q

occurs in both volanic and plutonic alkaline igneous groups
yellowish colored alteration called cancrinite
hexagonal
uniaxial difference from feldspar and optically megative distinguish from quartz low birefringes and low relief

A

nepheline

122
Q

predominant in alkali rich plutonic igneous rocks like syenites low relief blue color in hand specimen

A

sodalite

123
Q

found in alkalic bolcnic rocks tetragonal appears isometric low relief contians tiny inclusions within the mineral

A

leucite

124
Q

hexagonal and optically negatice occurs in al rich igneous and metamorphic rocks high refractive index shows bery high relief in think section low birefringes shows lamellar twinning

A

corundum

125
Q

isometric mineral occurs ultrabasic rocks like peridotite high concentrations of cr found in aal

A

spinel

126
Q

found in low silica mg rich igneous rocks assoc with olivine isometric opaque in thin section small inclusions of olivine

A

chromite

127
Q

major ore of fe isometric octahedral habit hardness 6 forms a solid solution with ulvospinel

A

magnetite

128
Q

mahor ore of ati accessory mineral found in volcanic and plutonic rocks solid solution with hematite occurs with magnetite hexagonal shows an elongated or acicular habit more equant crystals with an octahedral habit

A

ilmenite

129
Q

more oxidized than magentite forms and alteration product of magnetite and fe bearing minerals hexagonal form oolitic spherules

A

hematite

130
Q

ilmenite and hematite complete solid solution called rhombohedral magnetite and ulvospinel solid solution soinel series

A

iron titanium oxide geothermometer

131
Q

triclinic forms

A

pinacoids
pedions

132
Q

indices of pinacoids and pedions

A

{001} {010} {001} {0k1} {hk1} and variations

{hk1}

for review (33 decks)

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