biotite and muscovite

Question 1

A generally black or dark green form of mica that is a constituent of crystalline rocks and consists of a silicate of iron, magnesium, potassium, and aluminum.

Answer 1

Biotite

Question 2

Abundant in metamorphic rocks (both regional and contact), in pegmatites, and also in granites and other intrusive igneous rocks.

Answer 2

Biotite

Question 3

Also known as black mica.

Answer 3

Biotite

Question 4

Color of biotite

Answer 4

Brown to black (sometimes greenish)

Question 5

Specific Gravity of biotite

Answer 5

2.7-3.4

Question 6

Hardness of biotite

Answer 6

2.5-3

Question 7

Chemical formula of biotite

Answer 7

K(Mg,Fe)3 AISI3 O10(F,OH) 2

Question 8

Streak of biotite

Answer 8

White or gray

Question 9

Class of biotite

Answer 9

Silicates

Question 10

Transparency of biotite

Answer 10

Transparent or translucent

Question 11

Cleavage of biotite

Answer 11

Perfect Cleavage

Question 12

Biotite was named in honor to ______________, a French physicist, mathematician, and astronomer who researched the mica minerals for their optical properties.

Answer 12

Jean Baptiste Biot (1774-1862)

Question 13

Luster of biotite

Answer 13

Pearly luster

Question 14

Biotite is commonly used to limit the age of rocks through _____________ or _____________.

Answer 14

potassium-argon escort or argon -argon escort

Question 15

useful for evaluating the temperature histories of metamorphic rocks because the division of iron and magnesium between this and garnet is temperature
sensitive

Answer 15

biotite

Question 16

This is a common mineral that belongs to
the mica group.

Answer 16

Muscovite

Question 17

The name Muscovite derives from its use in window as ____________.

Answer 17

Muscovy glass

Question 18

In the _______ muscovite was mined for this use from pegmatites in the area around ___________.

Answer 18

1700s, Moscow, Russia

Question 19

Color of muscovite

Answer 19

can be colorless, white, or pale shades of pink, brown, green, or yellow

Question 20

Specific gravity of muscovite

Answer 20

2.8 to 2.9

Question 21

Hardness of muscovite

Answer 21

2.5-3

Question 22

Chemical formula of muscovite

Answer 22

KAl2(Si3AlO10)(OH)2

Question 23

Streak of muscovite

Answer 23

White, often sheds tiny flakes

Question 24

Class of muscovite

Answer 24

Silicates

Question 25

Transparency of muscovite

Answer 25

Transparent or translucent

Question 26

Cleavage of muscovite

Answer 26

Perfect Cleavage

Question 27

Luster of muscovite

Answer 27

Pearly to vitreous

Question 28

Formed in metamorphic, igneous, and sedimentary environments. It is a common mineral in metamorphic rocks, especially in schist and gneiss.

Answer 28

Muscovite

Question 29

This can also be found in igneous rocks such as granite, pegmatite, and syenite. In these rocks, it typically forms as a result of hydrothermal alteration, which occurs when hot fluids circulate through the rock and alter the mineral composition.

Answer 29

Muscovite

Question 30

Muscovite is sometimes cut and polished into _________ and used in jewelry.

Answer 30

cabochons

Question 31

Muscovite has a number of industrial uses:

Answer 31

- filler in the production of rubber and plastics - insulating material in the electrical industry - component in building materials such as drywall and cement

Question 32

Muscovite is also used in the production of ___________, ___________, and ___________.

Answer 32

lubricants, cosmetics, and paints

Question 33

In addition to its industrial uses, muscovite is also used as a __________ and as a __________.

Answer 33

decorative stone, gemstone