Term | Definition |
Specular Hematite | 6 hardness
Uneven Fracture
Metallic Luster
Reddish-Brown Streak
Brittle Tenacity
Opaque Diaphaneity
Oxide Composition group
*Used for Iron ore |
Milky Quartz | 7 hardness
Uneven to conchoidal fracture
Vitreous/waxy/greasy luster
Brittle tenacity
Translucent diaphaneity
Silicate Composition group
*Used for Jewelry, Abrasives, rock former |
Muscovite | 2-2.5 hardness
1 direction (basal) cleavage
Waxy/greasy luster
Brittle tenacity
Translucent diaphaneity
Silicates Composition group
*Used for lubricant and insulation |
Crystal Garnet | 7 hardness
Uneven/conchoidal fracture
12 sided crystals (dodecahedral) crystal habit
Vitreous to resinous luster
Brittle tenacity
Opaque diaphaneity
Silicate Composition group
*Used for jewelry and abrasives |
Limonite | 1.5 hardness
Uneven fracture
Dull/earthy luster
Yellowish brown streak
Brittle tenacity
Opaque diaphaneity
Oxide Composition group
*Used for Iron Ore |
Hornblende | 5.5 hardness
2 directions @60 & 120 degree cleavage
Waxy/dull cleavage
Brittle tenacity
Opaque diaphaneity
Silicate Composition group
*Used for rock former |
Rose Quartz | 7 hardness
Uneven/conchoidal fracture
Vitreous/waxy/greasy luster
Brittle tenacity
Translucent diaphaneity
Silicate Composition group
*Used for Jewelry, Abrasives, rock former |
Plagioclase | 6-6.5 hardness
2 directions @ 90 degree cleavage
Vitreous/waxy/pearly luster
Brittle tenacity
Translucent/opaque diaphaneity
Silicate Composition group
*Used for rock former |
Hematite | 1.5 hardness
Uneven fracture
Dull/earthy luster
Reddish brown streak
Brittle tenacity
Opaque diaphaneity
Oxide Composition group
*Used for Iron Ore |
Halite | 2.5 hardness
3 directions @ 90 degree cleavage
Vitreous/greasy luster
Brittle tenacity
Transparent/translucent diaphaneity
Halide Composition group
*Used for Salt and preservation |
Pyrite | 6-6.5 hardness
Uneven/conchoidal fracture
Cubic crystal habit
Metallic luster
Greenish-black streak
Brittle tenacity
Opaque diaphaneity
Sulfide Composition group
*Used for Sulfuric acid and batteries |
Graphite | 1-2 hardness
Uneven fracture
Metallic/sub-metallic luster
Black/steel gray streak
Sectile tenacity
Opaque diaphaneity
Native element Composition group
*Used for lubricant and pencils |
Olivine | 6.5-7 hardness
Uneven to conchoidal fracture
Vitreous luster
Brittle tenacity
Translucent/opaque Diaphaneity
Silicate Composition group
*Used for jewelry and rock former |
Orthoclase | 6 hardness
2 directions @ 90 degrees cleavage
Vitreous/waxy/greasy luster
Brittle tenacity
Opaque diaphaneity
Silicate Composition group
*Used as a rock former |
Garnet | 7 hardness
Uneven/conchoidal fracture
Vitreous/waxy/greasy luster
Brittle tenacity
Translucent/opaque diaphaneity
Silicate Composition group
*Used for Jewelry, abrasives and rock former |
Amethyst (Quartz) | 7 hardness
Uneven/conchoidal fracture
Vitreous/waxy/greasy luster
Brittle tenacity
Translucent/Transparent diaphaneity
Silicate Composition group
*Used for Crystals, industry and rock former |
Galena | 3.5 hardness
3 directions @ 90 (cubic) degrees cleavage
Metallic luster
Gray streak
Brittle tenacity
Opaque diaphaneity
Sulfide Composition group
*Used for Lead ore |
Sulfur | 1.5-2.5 hardness
Uneven fracture
Resinous luster
Brittle tenacity
Transparent/translucent diaphaneity
Native element Composition group
*Used for Sulfuric acid, fertilizers, gunpoweder |
Fluorite | 4 hardness
4 direction cleavage
Vitreous/waxy/resinous lsuter
Brittle tenacity
Transparent/translucent diaphaneity
Halide Composition group
*Used for Flux in steel making, toothpaste |
Sphalerite | 3.5-4 hardness
6 direction cleavage
Resinous luster
Light yellow streak
Brittle tenacity
Opaque diaphaneity
Sulfide Composition group
*Used for zinc ore |
Dolomite | 3.5-4 hardness
3 directions @ 75 degree cleavage
Vitreous/pearly.waxy luster
Brittle tenacity
Transparent/translucent/opaque diaphaneity
Carbonate Composition group
*Used for rock former |
Corundum | 9 hardness
Uneven fracture
Dull luster
Brittle tenacity
Opaque diaphaneity
Oxide Composition group
*Used for abrasive, rock former |
Smokey quartz | 7 hardness
Uneven/conchoidal fracture
Vitreous/waxy/greasy luster
Brittle tenacity
Translucent/opaque diaphaneity
Silicate Composition group
*Used for industry, abrasive, rock former |
Copper | 2.5-3 hardness
Uneven/irregular fracture
Metallic luster
Copper-red streak
Malleable tenacity
Opaque diaphaneity
Native element Composition group
*Used for Wiring, metal alloys, heat exchangers |
Quartz crystal | 7 hardness
Uneven/conchoidal fracture
6-sided crystal w/ triangular termination faces - crystal habit
Vitreous luster
Brittle tenacity
Translucent diaphaneity
Silicate Composition group
*Used for jewelry, abrasives, rock former |
Chalcopyrite | 3.5-4 hardness
Uneven or irregular fracture
Metallic luster
Greenish-black streak
Brittle tenacity
Opaque diaphaneity
Sulfide Composition group
*Used for copper ore |
Calcite | 3 hardness
3 directions @ 75 degree (rhombic) cleavage
Vitreous/waxy/dull luster
Brittle tenacity
Transparent/Translucent/Opaque diaphaneity
Carbonate Composition group
*Used as rock former |
Magnetite | 6 hardness
Uneven fracture
Metallic luster
Black streak
Brittle tenacity
Opaque diaphaneity
Oxide Composition group
*Used as Iron ore |
Biotite | 2.5-3 hardness
1 direction (basal cleavage)
Resinous/sub-resinous luster
Elastic tenacity
Opaque/transparent diaphaneity
Silicate Composition group
*Used for lubricant |
Augite | 6 hardness
2 directions @ 90 degrees cleavage
Waxy/dull luster
Brittle tenacity
opaque diaphaneity
Silicate Composition group
*Used as rock former |
Talc | 1 hardness
Good in 1 direction (basal) cleavage
Pearly or silky cleavage
Sectile Tenacity
Translucent/opaque diaphaneity
Silciate Composition group
*Used for powder |
Apatite | 5 hardness
Uneven or irregular fracture
Viretous/Sub-resinous/dull luster
Brittle tenacity
Opaque diaphaneity
Phosphate Composition group
*Used as fertilizer |
Gypsum | 2 hardness
Good in 1, poor in 2 cleavage
Vitreous, pearly or silky luster
Flexible tenacity
Transparent/opaque diaphaneity
Sulfate Composition group
*Used as Soil conditioner, sheetrock, plaster of paris |