mineral groups Flashcards

Question

enumerate: SULFATES Anhydrite (CaSO4) Form cleavage hardness SG remarks

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

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.

Answer 5

collophane

Answer 6

phosphorite or phosphate rock.

Answer 7

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.

Answer 8

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.

Answer 9

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

Answer 10

9. SPINEL (MgAl2O4) 10. MAGNETITE (Fe3O4) 11. CHROMITE (FeCr2O4)

Answer 11

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

Answer 12

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

Answer 13

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.

Answer 14

ruby copper.”

Answer 15

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.

Answer 16

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,

Answer 17

red orcher specularite

Answer 18

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.

Answer 19

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.

Answer 20

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.

Answer 21

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

Answer 22

stream tin.

Answer 23

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.

Answer 24

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.

Answer 25

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.

Answer 26

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.

Answer 27

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.

Answer 28

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.

Answer 29

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.

Answer 30

psilomelane

Answer 31

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.

Answer 32

LIMONITE FeO(OH)·nH2O

Answer 33

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.

Answer 34

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.

Answer 35

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.

Answer 36

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.

Answer 37

1. Gold (Au) 2. Silver (Ag) Copper (Cu) 4. Sulfur (S) 5. Diamond (C) 6. Graphite (C)

Answer 38

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)

Answer 39

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.

Answer 40

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.

Answer 41

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.

Answer 42

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.

Answer 43

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.

Answer 44

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).

Answer 45

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.

Answer 46

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.

Answer 47

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.

Answer 48

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.

Answer 49

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.

Answer 50

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.

Answer 51

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.)

Answer 52

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,

Answer 53

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.

Answer 54

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.

Answer 55

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.

Answer 56

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.

Answer 57

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.

Answer 58

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.

Answer 59

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.

Answer 60

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.

Answer 61

Orthochemical

Answer 62

Allochemical

Answer 63

Terrigenous sedimentary rocks

Answer 64

Conglomerates and breccias -

Answer 65

Agglomerates or volcanic breccia

Answer 66

Sandstones

Answer 67

Volcaniclastics

Answer 68

lithic arenite

Answer 69

felspathic arenite

Answer 70

quartz arenite

Answer 71

Dolomitization Allochemical Carbonate Rocks

Answer 72

Microcrystalline ooze Sparry calcite cement

Answer 73

Intraclasts

Answer 74

Type 1 Type 2

Answer 75

Dunham's Classification of Limestones

Answer 76

Wackestone

Answer 77

Grainstone

Answer 78

Boundstone

Answer 79

Orthochemical sedimentary rocks

Answer 80

1929-2018 1924-1994

Answer 81

dunham folks

Answer 82

mudsupported wackestone

Answer 83

grainstone calcite amtrix:sparite

Answer 84

floatstone

Answer 85

iron titanium oxide geothermometer

Answer 86

pinacoids pedions

Answer 87

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