CARBONATES/Calcite group

Question 1

CaCO3

Answer 1

Calcite

Question 2

Hexagonal. Crystals extremely varies in habit and often complex. It is usually in crystal or in coarse to fine grained aggregates. Usually found in cave deposits.

Answer 2

Calcite

Question 3

The three important habits of calcite

Answer 3

prismatic, rhombohedral, and scalenohedral

Question 4

Hardness of calcite

Answer 4

3

Question 5

Specific gravity of calcite

Answer 5

2.7

Question 6

What are the usual color of calcite?

Answer 6

usually white to calcite but can be tinted gray, red, green, blue, yellow

Question 7

It is the main mineral of chalk and its main constituents of limestone and of marble, metamorphosed limestone.

Answer 7

Calcite

Question 8

Cellular deposits formed around hot and cold calcareous springs.

Answer 8

Travertine or tufa

Question 9

Calcite can be a primary mineral of igneous rock such as ______, _______, and ______.

Answer 9

carbonatites, nepheline, and syenite

Question 10

MgCO3

Answer 10

Magnesite

Question 11

The crystal form is rarely rhombohedral and usually in cyrptocrystalline in white.

Answer 11

Magnesite

Question 12

The cleavage is rhombohedral perfect

Answer 12

Magnesite

Question 13

Has a specific gravity of 3.0 - 3.2

Answer 13

Magnesite

Question 14

What is the hardness of magnesite?

Answer 14

3.5 - 5

Question 15

What are the usual color of magnesite?

Answer 15

White, gray, yellow, brown. Luster vitreous. Transparent to translucent.

Question 16

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

Answer 16

Magnesite

Question 17

Calcite that is not reactive to HCl but dissolves with effervescence in hot HCL.

Answer 17

Magnesite

Question 18

FeCO3

Answer 18

Siderite

Question 19

Commonly in rhombohedral crystal, which may show curved faces. Also in globular concretions and cleavable masses. May be botryoidal, compact, and earthy.

Answer 19

Siderite

Question 20

Has also a rhombohedral perfect cleavage

Answer 20

Siderite

Question 21

What is the hardness of siderite

Answer 21

3.5 - 4

Question 22

Has a specific gravity of 3.96 for pure

Answer 22

Siderite

Question 23

Associated with ores containing silver minerals, pyrite, chalcopyrite, and galena. it also occurs as clay ironstone and can be found in shales and coal measures as blackband ore.

Answer 23

Siderite

Question 24

Soluble in powdered form in cold HCL or as fragments in hot HCL with effervescene.

Answer 24

Siderite

Question 25

MnCO3

Answer 25

Rhodocrosite

Question 26

Usually cleavable, massive and granular to compact.

Answer 26

Rhodocrosite

Question 27

What is the hardness of of rhodocrosite?

Answer 27

3.5 - 4

Question 28

Has a specific gravity of 3.5 to 3.7

Answer 28

Rhodocrosite

Question 29

Has a usual shade of rose red and maybe light pink to dark brown.

Answer 29

Rhodocrosite

Question 30

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

Answer 30

Rhodocrosite

Question 31

Usually reniform, botryoidal, or stalactitic. Rarely in small rhombohedral or scalenohedral crystals.

Answer 31

Smithsonite

Question 32

ZnCO3

Answer 32

Smithsonite

Question 33

Smithsonite has a hardness of ________.

Answer 33

4 - 4.5

Question 34

It has a specific gravity of 4.30 - 4.45

Answer 34

Smithsonite

Question 35

Often dirty brown; may also be colorless, white, green, blue, or pink. The yellow variety is known as turkey-fat ore.

Answer 35

Smithsonite

Question 36

A zinc ore of supergene origin, usually found with zinc deposits in limestones. Associated with sphalerite, galena, hemimorphite, cerussite, calcite, and limonite.

Answer 36

Smithsonite