Introductory mineralogy virtual sample set

Here are 16 samples (or sample sets) of minerals that you will use to answer lab questions. Examine each sample in detail by zooming in and exploring its composition and texture.

Sample set A:

Sample A (all four) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 3 white Excellent; 3 directions, NOT at 90° to each other No fizzes when HCl is applied

Sample B:

Sample B (both) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
metallic 2.5 gray to dark gray 3, at 90° No Very dense (specific gravity = 7.5); stinks of hydrogen sulfide (rotten egg smell) if HCl is applied.

Sample set C:

Sample C1 (left) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 1 – 6 brick red No No (none)

Sample C2 (right) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
metallic 1 – 6 brick red No No (none)

Sample D:

Sample D has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 7 (too hard to streak) No Brittle; may show parting Dodecahedral crystals are distinctive.

Sample E:

Sample E (both) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 2 – 2.5 white 1 (perfect) No can be split into thin, flexible sheets

Sample F:

Sample F has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 6 white 2, at 90° No lamellae

Sample G:

Sample G (both) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 2.5 – 3 gray-brown to white 1 (excellent) No can be split into thin, flexible sheets

Sample set H:

Sample H1 (left) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 6-6.5 dark gray Absent No magnetic

Sample H2 (middle) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 6 white 2, at 90° No lamellae

Sample H3 (right) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
metallic 2.5 gray to dark gray 3, at 90° No Very dense (specific gravity = 7.5); stinks of hydrogen sulfide (rotten egg smell) if HCl is applied.

 

Sample I:

Sample I has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
metallic 6-6.5 dark gray absent No often forms cubes, sometimes with striations

 

Sample set J:

Sample J1 (left) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 5.5-6 white to pale gray Good. 2 planes, at about 60°/120° to each other No color dark gray to black; forms prisms.

Sample J2 (right) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 5.5-6 white to pale gray Moderate. 2 planes, at about 90° to each other No color dark green to brown or black; forms short, 8-sided prisms

 

Sample K:

Sample K has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 2-5 white absent No often forms dull or silky masses and asbestos (fibrous) forms.

 

Sample set L:

Sample L1 (left) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 2 white Good in 1 direction; poor in 2 more directions. No Forms tabular crystals, prisms, or blades. Transparent when pure; translucent when impurities are present.

Sample L2 (right) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 1 white Absent No Very soft. Feels soapy to the touch.

 

Sample M:

Sample M (all four) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 7 None (too hard to streak) Absent Conchoidal No reaction to HCl. Comes in many colors.

 

Sample set N:

Sample N1 (left) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 2.5 white Excellent: 3 planes at 90° to each other (so it breaks into cubes) No Tastes salty.

Sample N2 (right) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 4 white Excellent: 4 planes No Often colorless (so it would appear black on a black background, like you see here), or translucent purple or green.

 

Sample O:

Sample O (both) has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
nonmetallic 3.5-4 White Excellent; 3 directions, NOT at 90° to each other none Reaction to HCl occurs only if the mineral is powdered first.

 

Sample P:

Sample P has the following properties:

Luster Hardness Color of streak Cleavage? Fracture? Other properties
metallic 1 Dark gray Excellent in 1 direction none Greasy feel. Exceptionally soft.