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Correl > Day 2 Mineralogy > Flashcards

Day 2 Mineralogy Flashcards

1
Q

What are the three major carbonate groups?

A

Calcite group, Aragonite group, Dolomite group

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2
Q

One of the most common rock-forming minerals, its crystals are extremely varied in habit and often complex. Important habits are prismatic, rhombohedral, and scalenohedral. Usually in crystals or in coarse- to fine-grained aggregates, and has rhombohedral perfect cleavage.

A

Calcite

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3
Q

The chemically pure and optically colorless variety of calcite

A

Iceland spar

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4
Q

Cellular deposits formed around hot or cold calcareous springs are known as?

A

travertine or tufa

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5
Q

Calcite is a late crystallization product in the cavities of lavas and is also a common mineral in hydrothermal veins associated with ____________

A

sulfide ores

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6
Q

Calcite may also be a primary mineral in some igneous rocks such as ____________ and ____________

A

carbonatites and nepheline syenite

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7
Q

Common as stalagmites, stalactites, and incrustations in cave deposits

A

Calcite

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8
Q

How is calcite distinguished from dolomite?

A

coarse fragments of calcite effervesce freely in cold dilute HCl

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9
Q

How is calcite distinguished from aragonite?

A

lower specific gravity and rhombohedral cleavage

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10
Q

Common in veins and irregular masses derived from the alteration of Mg-rich metamorphic and igneous rocks, and is a constituent of serpentinites and altered peridotites.

A

Magnesite

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11
Q

Magnesite that are a constituent of serpentinite is compact and cryptocrystalline and may be associated with ___________

A

opaline silica

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12
Q

This magnesite is found in talc, chlorite, and mica schists and in dolomitic limestones.

A

Cleavable magnesite

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13
Q

The white massive variety of magnesite resembles chert. How is magnesite distinguished from chert?

A

Magnesite has a lower degree of hardness (vs Chert)

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14
Q

How are cleavable magnesites are distinguished from dolomite?

A

by higher specific gravity

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15
Q

True or False: Magnesite dissolves in cold HCl.

A

False. Magnesite is almost nonreactive in cold HCl, but dissolves with effervescence in hot HCl.

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16
Q

As a vein mineral, in well-crystallized form, it is associated with metallic ores containing silver minerals, pyrite, chalcopyrite, and galena.

A

Siderite

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17
Q

Siderite with admixed clay minerals, in concretions with concentric layers

A

clay ironstone

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18
Q

Siderite found in shales and coal, contaminated with carbonaceous material.

A

blackband ore

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19
Q

Siderite is a common constituent of _________________, in association with chert and magnetite.

A

sedimentary Precambrian iron-formations

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20
Q

What causes the brownish color of siderite?

A

presence of iron

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21
Q

What distinguishes siderite from other carbonates?

A

Its brownish color and high specific gravity

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22
Q

How is siderite distinguished from sphalerite?

A

by its rhombohedral cleavage

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23
Q

True or False: Siderite is soluble as fragments in cold HCl.

A

False. Siderite is soluble in powdered form in cold HCI, and as fragments in hot HCI with effervescence.

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24
Q

A constituent of hydrothermal veins with ore minerals of silver, lead, and copper, and of manganese deposits.

A

Rhodochrosite

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25
Q

What are the two diagnostic characteristics of rhodochrosite?

A

Its pink color and rhombohedral cleavage

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26
Q

What distinguishes rhodochrosite from rhodonite?

A

Hardness. Rhodochrosite has a hardness of 4, while Rhodonite has 6.

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27
Q

True or False: Rhodochrosite is not soluble in HCl.

A

False. Rhodochrosite is soluble in hot HCI with effervescence

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28
Q

Usually reniform, botryoidal, or stalactitic, and is often dirty brown in color.

A

Smithsonite

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29
Q

The yellow smithsonite variety

A

turkey-fat ore

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30
Q

Mineral of supergene origin, usually found with zinc deposits in limestones, and associated with sphalerite, galena, hemimorphite, cerussite, calcite, and limonite.

A

Smithsonite

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31
Q

True or False: Smithsonite effervesces in powdered form and in cold HCl.

A

False. Smithsonite effervesces in powdered form and in hot HCI.

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32
Q

The orthorhombic polymorph of calcite, deposited from hot springs, and associated with gypsum.

A

Aragonite

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33
Q

Aragonite occurs as __________ on serpentine and in ___________ in basalt.

A

fibrous crusts; amygdaloidal cavities

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34
Q

As a result of crystallization at high pressure but relatively low temperature, aragonite occurs in metamorphic assemblages of which facies?

A

blueschist facies

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35
Q

The pearly layer of many shells and the pearl itself is what mineral?

A

Aragonite

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36
Q

Columnar aragonite has cleavage parallel to ____________

A

elongation

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37
Q

How is aragonite distinguished from witherite and strontianite?

A

by lower specific gravity and lack of distinctive flame coloration.

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38
Q

True or False: Aragonite does not effervesce in HCl.

A

False. Aragonite effervesces in cold, dilute HCl

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39
Q

In hydrothermal veins associated with galena.

A

Witherite

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40
Q

A sulfate mineral that occurs most commonly in hydrothermal veins associated with ores of silver, lead, copper, cobalt, and manganese.

A

Barite

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41
Q

Chemical formula of Barite

A

BaSO4

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42
Q

A sulfate mineral that is recognized by its high specific gravity, characteristic cleavage, and crystal form. Gives a yellowish-green flame test.

A

Barite

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43
Q

(Sulfate) Orthorhombic crystals closely resemble those of barite. Commonly tabular on {001} or prismatic parallel to the a or b axis. Also radiating fibrous; granular.

A

Celestite

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44
Q

Chemical formula for Celestite

A

SrSO4

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45
Q

T or F. Celestite occurs most commonly as disseminations through limestone or sandstone, or in nests and lining cavities in such rocks.

A

T

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46
Q

How is celestite differentiated from barite?

A

lower specific gravity and a crimson flame test (for Sr)

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47
Q

What are the characteristic habits of some celestite?

A

Fine radiating or fibrous habit

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48
Q

What is the usual color of celestite?

A

Pale blue

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49
Q

Chemical formula for Anglesite

A

PbSO4

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50
Q

Closely resembles barite but is differentiated by lower specific gravity and a crimson flame test (for Sr).

A

Celestite

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51
Q

Sulfate mineral which is adamantine when crystalline, dull when earthy

A

Anglesite

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52
Q

Anglesite is frequently earthy, in concentric layers that may have an unaltered core of what mineral

A

Galena

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53
Q

(Sulfate) A common supergene mineral found in the oxidized portions of lead deposits. Associated with galena, cerussite, sphalerite, smithsonite, hemimorphite, and iron oxides.

A

Anglesite

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54
Q

Anglesite may become dark gray. What causes this?

A

Impurities

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55
Q

A sulfate mineral that is recognized by its high specific gravity, its adamantine luster, and its common association with galena.

A

Anglesite

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56
Q

A common supergene mineral found in the oxidized portions of lead deposits. Associated with galena, cerussite, sphalerite, smithsonite, hemimorphite, and iron oxides.

A

Anglesite

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57
Q

Chemical formula of Anglesite

A

PbSO4

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58
Q

What makes anglesite recognized from other minerals?

A

high specific gravity, adamantine luster, and its common association with galena

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59
Q

Which sulfate mineral has the highest specific gravity and why?

A

Anglesite; because of the presence of lead
SG= 6.2-6.4

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60
Q

This mineral has a usually massive or in crystalline masses resembling an isometric mineral with cubic cleavage; it has three pinacoidal cleavages

A

Anhydrite

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61
Q

What is the chemical formula for Anhydrite

A

CaSO4

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62
Q

Anhydrite is found in the same manner, but less commonly- occurring as

A

Gypsum

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63
Q

What is the usual color of anhydrite?

A

colorless to bluish or violet

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64
Q

Occurs in beds associated with salt deposits in the cap rock of salt domes, and in limestones; also in amygdaloidal cavities in basalts

A

Anhydrite

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65
Q

T or F. Anhydrite s found in much the same manner as gypsum, with which it is commonly associated, but is more abundant than gypsum

A

F. less common

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66
Q

How is anhydrite distinguished from calcite?

A

higher specific gravity

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67
Q

How is anhydrite distinguished from gypsum?

A

greater hardness (anhydrite) and water content (of gypsum)

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68
Q

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.

A

Anhydrite

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69
Q

Commonly tabular on {010}; diamond-shaped with beveled edges. Twinning on {100} common, resulting in swallowtail twins; Commonly distributed in sedimentary rocks, often as thick beds.

A

Gypsum

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70
Q

What will happen if you hydrate your anhydrite?

A

It will turn to gypsum

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71
Q

What is the chemical formula for gypsum

A

CaSO4·2H2O

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72
Q

A fibrous gypsum with silky luster

A

Satin spar

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73
Q

Fine-grained massive variety of gypsum

A

Alabaster

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74
Q

A gypsum variety that yields broad, colorless, and transparent cleavage folia.

A

Selenite

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75
Q

Gypsum is frequently formed by the alternation of?

A

Anhydrite

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76
Q

Gypsum is found as a __________ mineral in metallic veins

A

gangue

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77
Q

______ is a gypsum variety that yields broad, colorless, and transparent cleavage folia.

A

Selenite

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78
Q

T or F. Gypsum is commonly distributed in metamorphic rocks, often as thick beds

A

F. Gypsum is commonly distributed in sedimentary rocks, often as thick beds

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79
Q

Chemical formula of gypsum

A

CaSO4·2H2O

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80
Q

Usually as rhombohedra, often with curved faces, and when strongly curved known as “saddle-shaped” crystals

A

Dolomite

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81
Q

Generally not found in well-formed crystals; When in crystals, they resemble those of dolomite.

A

Ankerite

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82
Q

Ankerite is typically yellowish white. What causes it to become yellowish brown?

A

Oxidation (due to some of the iron)

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83
Q

Occurrence of dolomite is most common in sedimentary rocks as

A

dolomite or dolostone

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84
Q

A tungstate mineral recognized by its high specific gravity, crystal form, fluorescence in shortwave ultraviolet light, and generally light color.

A

Scheelite

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85
Q

Most scheelite will fluoresce with ________ color in short ultraviolet radiation.

A

bluish-white

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86
Q

What type of marble does dolomite occur as?

A

Dolomitic marble

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87
Q

Found in granite pegmatites, contact metamorphic deposits, and high-temperature hydrothermal veins associated with granitic rocks.

A

Scheelite

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88
Q

Ankerite is a common carbonate in Precambrian iron-formations in association with?

A

chert, magnetite, and hematite

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89
Q

Scheelite is commonly associated with these minerals

A

cassiterite, topaz, fluorite, apatite, and molybdenite

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90
Q

Dolomite occurs as a hydrothermal vein mineral, especially in________ and ________ veins that traverse limestone, associated with fluorite, calcite, barite, and siderite.

A

lead, zinc

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91
Q

SG and hardness of Scheelite

A

SG= 5.9-6.1
hardness = 4.5-5

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92
Q

Chemical formula for scheelite

A

CaWO4

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93
Q

Name 3 phosphates

A

Apatite, Amblygonite, Turquoise

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94
Q

Phosphate materials of _______ and ______ are members of the apatite group

A

bones and teeth

95
Q

(phosphate) Can be scratched by knife

A

Apatite (hardness= 5); knife= 5.5

96
Q

The variety __________ (a massive, cryptocrystalline type) constitutes the bulk of phosphorite or phosphate rock

A

collophane

97
Q

Usually recognized by a combination of its color, hexagonal crystal form, and hardness. It is distinguished from beryl by inferior hardness and from quartz by color and hardness

A

Apatite

98
Q

Chemical formula of apatite

A

CaAl5(PO4)3(F, Cl, OH)

99
Q

Found mainly in Li-bearing granite pegmatites in association with spodumene, tourmaline, lepidolite, and apatite

A

Amblygonite

100
Q

In a flame test, amblygonite will give ______________ color due to presence of ____ element

A

diagnostic red; Li

101
Q

Hardness of Amblygonite

A

6

102
Q

chemical formula of amblygonite

A

LiAl(PO4)(F, OH)

103
Q

This phosphate mineral transmit light on thin edges

A

Turquoise

104
Q

Dolomite and ankerite have similar properties except for the color differences. Dolomite has color variations of colorless, white, gray, green, or some shade of light pink, or flesh color, while Ankerite has the color variations of ___________.

A

yellowish white to yellowish brown

105
Q

A secondary mineral found in small veins and stringers traversing more or less decomposed volcanic rocks in arid regions.

A

Turquoise

106
Q

Turquoise is easily recognized by its color. It is harder than ________, the only common mineral that it resembles

A

chrysocolla

107
Q

Turquoise has a _________ luster

A

wax-like

108
Q

Cuprite occurs as ruby red in transparent crystals, and it is called

A

Ruby copper

109
Q

Usually distinguished by its red color, isometric crystal form, high luster, brown, streak, and association with limonite.

A

Cuprite

110
Q

Chemical formula of cuprite

A

Cu2O

111
Q

Characterized chiefly by its great hardness, high luster, specific gravity, and parting. It may display hexagonal dipyramids that are rounded into barrel shapes with deep horizontal striations.

A

Corundum

112
Q

Chemical formula of corundum

A

Al2O3

113
Q

Hardness of Corundum

A

9

114
Q

Corundum also occurs as __________ in detrital soil and stream sands.

A

rolled pebbles

115
Q

Distinguished mainly by its characteristic red streak, reddish-brown to black color, and earthy to metallic luster. It is the most abundant iron ore mineral in Precambrian banded iron-formations.

A

Hematite

116
Q

Chemical formula of hematite

A

Fe2O3

117
Q

Red earthy variety of hematite

A

Red ocher

118
Q

Platy and metallic variety of hematite

A

Specularite

119
Q

Micaceous and foliated hematite

A

Specular hematite

120
Q

Hematite with botryoidal to reniform shapes with radiating structures

A

Kidney ore

121
Q

How is ilmenite distinguished from hematite?

A

streak

122
Q

How is ilmenite distinguished from magnetite?

A

lack of strong magnetism

123
Q

A common accessory in igneous rocks. May occur as large masses in gabbros, diorites, and anorthosites, commonly associated with magnetite. Most commonly massive and compact, also in grains or as sand.

A

Ilmenite

124
Q

Chemical formula of ilmenite

A

FeTiO3

125
Q

Characterized by its adamantine luster and red color. Usually subtranslucent, may be transparent. Commonly in tetragonal, prismatic crystals with dipyramid terminations and vertically striated prism faces. Frequently in elbow twins. Habit of crystals may be slender acicular.

A

Rutile

126
Q

Chemical formula of rutile

A

TiO2

127
Q

How is rutile distinguished from cassiterite?

A

Lower specific gravity

128
Q

Rutile may be included in which two minerals as a fine-grained slender crystals?

A

Quartz and Mica

129
Q

Usually in radiating fibers or columns. Also granular massive; often in reniform coats and dendritic shapes finely overgrown with other Mn-oxides and hydroxides. Frequently pseudomorphous after manganite. Iron black streak.

A

Pyrolusite

130
Q

Chemical formula of pyrolusite

A

MnO2

131
Q

Coarsely crystalline pyrolusite has a hardness of 6-6.5. What is this variation called?

A

Polianite

132
Q

It is found as nodular deposits in bogs, on lake bottoms, and on the floors of oceans. Also occurs in veins associated with quartz and various metallic minerals. It is the most common manganese ore mineral and is widespread in its occurrence.

A

Pyrolusite

133
Q

Recognized by its high specific gravity, adamantine luster, and light streak. Present as an accessory mineral of igneous rocks and pegmatites, but most commonly found in high-temperature hydrothermal veins in or near granitic rocks.

A

Cassiterite

134
Q

Chemical formula of cassiterite

A

SnO2

135
Q

Cassiterite in reniform shapes with radiating fibrous appearance is called?

A

Wood tin

136
Q

Cassiterite variation that may also occur as rolled pebbles in placer deposits

A

Stream tin

137
Q

Characterized chiefly by its pitchy luster, high specific gravity, color, streak, and strong radioactivity (as detected by a Geiger counter or scintillation counter).

A

Uraninite

138
Q

Most commonly as massive or botryoidal forms with a banded structure variation of Uraninite

A

Pitchblende

139
Q

Chemical formula of uraninite

A

UO2

140
Q

Isometric. Recognized by its hardness, octahedral crystal form, and vitreous luster. Common in twinned octahedrons. Dodecahedron may be present as small truncations but other forms are rare. Also massive and in irregular grains.

A

Spinel

141
Q

The metamorphic assemblages of spinel may contain

A

phlogopite, pyrrhotite, and graphite

142
Q

Chemical formula of spinel

A

MgAl2O4

143
Q

Isometric. Frequently in octahedral crystals, more rarely in dodecahedrons. Other forms rare. Usually granular massive, coarse- or fine-grained. Characterized by its strong magnetism, black color, and hardness of 6.

A

Magnetite

144
Q

Chemical formula of magnetite

A

Fe3O4

145
Q

Magnetite may act as a natural magnet, and it is known as

A

Lodestone

146
Q

Magnetite is often closely intergrown with corundum, forming ___________.

A

Emery

147
Q

Isometric, with octahedral habit, but crystals rare. Commonly massive, granular to compact. Association with olivine and serpentine is highly characteristic.

A

Chromite

148
Q

How is chromite distinguished from magnetite?

A

Lack of magnetism and brown streak

149
Q

Chemical formula of chromite

A

FeCr2O4

150
Q

Recognized by its foliated nature, light color, and pearly luster on cleavage faces. Found in association with serpentine dolomite, magnetite, and chromite. As a reaction product of Mg-silicates, especially serpentine. Basal {0001} perfect. Folia flexible but not elastic. Sectile.

A

Brucite

151
Q

Chemical formula of brucite

A

Mg(OH)2

152
Q

How is brucite distinguished from talc?

A

by being considerably harder

153
Q

How is brucite distinguished from mica?

A

by being inelastic

154
Q

Its black color and prismatic crystals are most diagnostic. Monoclinic crystals that are prismatic parallel to the c axis and vertically striated. Often columnar to coarse – fibrous. Contact and penetration twins common.

A

Manganite

155
Q

Chemical formula of manganite

A

MnO(OH)

156
Q

How is manganite distinguished from pyrolusite?

A

Hardness (4) and brown streak

157
Q

A product of secondary alteration of original Mn-carbonates, Mn-silicates, or both. Generally in association with pyrolusite in manganese ore deposits, in nodular deposits in bogs, and on lake bottoms and on see and ocean floors. Massive, botryoidal, stalactitic; appears amorphous.

A

Romanechite

158
Q

How is romanechite distinguished from other oxide minerals?

A

its greater hardness (5-6) and botryoidal form

159
Q

How is romanechite distinguished from limonite?

A

by its black streak

160
Q

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

A

psilomelane

161
Q

Rarely in distinct prismatic (orthorhombic), vertically striated crystals. Generally massive, reniform, stalactitic, and in radiating fibrous aggregation. Foliated. A common mineral resulting from oxidation and weathering of iron-bearing minerals.

A

Goethite

162
Q

Chemical formula of goethite

A

FeO(OH)

163
Q

Generally loose and porous variation of goethite

A

Bog ore

164
Q

Goethite constitutes the gossan or ___________ over metalliferous vein deposits.

A

iron hat

165
Q

How is goethite distinguished from colloform hematite and romanechite?

A

by color and streak

166
Q

A field term used for very fine-grained to amorphous mixtures of brown ferric hydroxides whose real identities are unknown.

A

Limonite

167
Q

Chemical formula of limonite

A

FeO(OH)·nH2O

168
Q

Limonite has variable compositions and consists of a mixture of several iron hydroxides or of a mixture of several minerals such as hematite, goethite, or lepidochrocite, with or without additional ____________.

A

absorbed water

169
Q

Native mineral with crystal form commonly in irregular plates, scales, or masses. Also in rounded or flattened grains “nuggets”

A

Gold

170
Q

True or False: Bauxite is a mineral term.

A

False. Bauxite is a rock term.

171
Q

Bauxite consists of a very fine-grained intergrowth of three aluminum hydroxides namely:

A

diaspore, gibbsite, and boehmite

172
Q

T or F. Gold is very malleable and sectile. It fractures hackly

A

T

173
Q

Bauxite is the major ore of __________.

A

Aluminum

174
Q

Formed in the tropics, __________ is a soil consisting mainly of hydrous aluminum and ferric oxides.

A

Laterite

175
Q

Gold is usually in various shades of yellow depending on purity, becoming paler with increasing ______ content

A

silver

176
Q

Recognized by its light, commonly yellowish-brown color, pisolitic and earthy texture, and low degree of hardness.

A

Bauxite

177
Q

Name the 2 chief sources of gold

A

Hydrothermal gold - presence of gold cannot be detected with the eye
Placer deposits - gold occurs as fine detrital grains and nuggets

178
Q

How to distinguish gold from pyrite and chalcopyrite?

A

Pyrite- much greater hardness
Chalcopyrite - is brittle instead of malleable and sectile

179
Q

A term used to describe crystal shapes when the faces of the cube have grown more at the edges than in the center.

A

hopper-shaped

180
Q

Specific gravity of gold when pure

A

19.3

181
Q

Characterized by its cubic cleavage and salty taste. Occurs most commonly in evaporite deposits, associated with gypsum, anhydrite, dolomite, and shale.

A

Halite

182
Q

Chemical composition of halite

A

NaCl

183
Q

T or F. Presence of other metals increases the specific gravity of Gold.

A

F. Presence of other metals (usually silver) decreases the specific gravity of Gold, which may be as low as 15

184
Q

Valuable deposits are also found in intrusive masses known as ___________, which have their roots in thick, bedded deposits.

A

salt domes

185
Q

When in crystals or granular crystalline masses showing cubic cleavage, it is known as

A

Rock salt

186
Q

How is halite distinguished to sylvite?

A

by a less bitter taste and yellow flame color

187
Q

A native element with isometric crystal commonly malformed and branching, arborescent, or reticulated groups. Also in coarse or fine wire. Usually in irregular masses, plates, and scales

A

Silver

188
Q

Has the same origin, mode of occurrence, and associations as halite but is much rarer. Colorless to white; also shades of blue, yellow, or red caused by impurities. Transparent when pure.

A

Sylvite

189
Q

Chemical formula of sylvite

A

KCl

190
Q

Silver has SG of 2.5-3. Malleable and _________

A

ductile

191
Q

What causes the yellow flame color of halite?

A

Presence of sodium

192
Q

Give the SG of silver when pure and when impure

A

pure = 10.5
impure = 10-12

193
Q

Silver turns to what color when tarnished?

A

brown or gray-black

194
Q

Isometric, usually in cubes, and often in penetration twins. Other crystal forms are rare. Distinguished by its cubic crystals and perfect octahedral cleavage. Also by its vitreous luster and usually fine coloring, and by the fact that it can be scratched by a knife.

A

Fluorite

195
Q

Chemical formula of fluorite

A

CaF2

196
Q

Native silver in large deposits has been precipitated from ___________

A

primarily hydrothermal solutions

197
Q

Fluorite may be the ________ mineral in hydrothermal veins, and _______ mineral in metallic ores.

A

chief; gangue

198
Q

How is fluorite distinguished from calcite?

A

It is harder than calcite and does not effervesce with cold HCl.

199
Q

A native element which is usually in irregular masses, plates, and scales, and twisted and wirelike forms

A

Copper

200
Q

Copper is _________ on fresh surface, usually dark with dull luster because of ________

A

copper red; tarnish

201
Q

Primary deposits of native copper are associated with basaltic lavas, where copper was deposited through the reaction of ___________ with ___________ minerals.

A

hydrothermal solutions; iron-oxide

202
Q

SG of native copper

A

8.9

203
Q

A native mineral with massive crystal habit, reniform, stalactitic, as incrustations, earthy.

A

Sulfur

204
Q

It is found near the crater rims of active or extinct volcanoes, deposited from volcanic gases. It also occurs in veins with the metallic sulfides formed by the oxidation of the sulfides

A

sulfur

205
Q

T or F. Sulfur is a good conductor of heat.

A

F. poor conductor

206
Q

What happens to sulfur crystal when held close to the ear?

A

You will hear it crack.

207
Q

How to distinguish sulfur from orpiment?

A

sulfur = absence of cleavage

208
Q

______ is a variety of diamond, has rounded forms and a rough exterior resulting from a radial or cryptocrystalline aggregate. The term is also applied to badly colored or flawed diamonds without gem value

A

Bort

209
Q

Hardest known mineral

A

Diamond

210
Q

_______________ is a black or grayish-black bort. It is noncleavable, opaque and less brittle than crystals

A

Carbonado/carbon

211
Q

The primary occurrence of diamonds is in altered peridotite called ______________, as intrusive bodies that are commonly circular with pipelike shape and referred to as “diamond pipes”

A

kimberlite

212
Q

A large percentage of the diamonds are recovered from alluvial deposit known as _______

A

placers

213
Q

synthetic diamonds are called

A

cubic zirconia

214
Q

1 carat of diamond is equivalent to how many milligrams?

A

200 mg

215
Q

A native element with characteristic “greasy feel”

A

graphite

216
Q

T or F. Graphite occurs commonly in metamorphic rocks such as crystalline limestones, schists, and gneisses.

A

T

217
Q

Distinguishing properties of graphite from molybdenite

A

graphite= black color; black streak
molybdenite= blue tone; grayish-black streak

218
Q

Sulfide mineral the most commonly have massive and very fine-grained crystal form. This is one of the most important copper ore minerals.

A

Chalcocite

219
Q

Chalcocite is usually shinning lead gray, tarnished to dull black upon ___________

A

exposure

220
Q

Chalcocite is also a constituent of “_________________” deposits disseminated throughout porphyritic granodiorite intrusives

A

porphyry copper

221
Q

Chemical formula of chalcocite

A

Cu2S

222
Q

A usually massive sulfide which occurs less frequently as supergene mineral in the upper enriched parts of the copper veins.

A

bornite

223
Q

It is distinguished by its characteristic brown color on the fresh fracture and the purple tarnish

A

bornite

224
Q

Bornite is also known as _____________

A

peacock ore

225
Q

chemical formula for bornite

A

Cu5FeS4

226
Q

A very common metallic sulfide mineral is recognized by its good cubic cleavage, high specific gravity, softness, lead-gray color and streak. It is found in veins associated with sphalerite, marcasite, chalcopyrite, etc.

A

Galena

227
Q

SG of Galena

A

7.4-7.6

228
Q

Why do galena have relatively high SG compared to other sulfides?

A

Due to the presence of Pb

229
Q

Chemical formula of Galena

A

PbS

230
Q

Isometric sulfide mineral with tetrahedron, dodecahedron, and cube as common forms. Is the common ore mineral for zinc.

A

Sphalerite

231
Q

Sphalerite is ________ when pure and _____________ when nearly so.

A

colorless; green

232
Q

Sphalerite has _________ luster and ______________ streak

A

resinous; white to yellow and brown

233
Q

Chemical formula for Sphalerite

A

ZnS

Correl (18 decks)

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