Sulfide Mineral Identification: Properties and Characteristics

Sulfide and Sulfosalt Mineral Properties

This document details the key physical and chemical properties of various sulfide and sulfosalt minerals, focusing on characteristics such as Hardness, Habit, Fracture, Tenacity, Color, Luster, Diaphaneity, and Streak.

Hardness (H)

Measured on the Mohs scale.

Fracture

How the mineral breaks (e.g., Conchoidal, Irregular).

Tenacity

Resistance to breaking (e.g., Fragile, Sectile, Malleable, Flexible).

Luster (Brillo)

Appearance in reflected light (e.g., Metallic, Adamantine, Resinous).

Diaphaneity

Transparency (Opaque or Translucent).

Streak (Raya)

Color of the mineral's powder.

Argentite ($ ext{Ag}_2 ext{S}$)

• Chemical Formula: $ ext{Ag}_2 ext{S}$
• Habit: Filamentary, Dendritic, Subconchoidal.
• Color: Black.
• Luster: Metallic, Matte.
• Tenacity: Malleable, Sectile.
• Hardness (H): 2.0 – 2.5
• Streak: Gray to Black.
• Diaphaneity: Opaque.

Chalcocite ($ ext{Cu}_2 ext{S}$)

• Chemical Formula: $ ext{Cu}_2 ext{S}$
• Habit: Compact and Massive, Prismatic.
• Color/Patina: Gray to Black, metallic, matte patina with blue reflections.
• Fracture: Conchoidal.
• Tenacity: Sectile.
• Hardness (H): 2.5 – 3.0
• Streak: Grayish-Black.
• Diaphaneity: Opaque.

Covellite ($ ext{CuS}$)

• Chemical Formula: $ ext{CuS}$
• Habit: Irregular, Scarce Glassy appearance.
• Color: Dark Blue.
• Luster: Dark Metallic, Resinous, Submetallic.
• Tenacity: Flexible.
• Hardness (H): 1.5 – 2.0
• Streak: Gray to Black.
• Diaphaneity: Opaque.

Bornite ($ ext{Cu}_5 ext{FeS}_4$)

• Chemical Formula: $ ext{Cu}_5 ext{FeS}_4$
• Crystal System: Cubic.
• Color: Bronze Brown-Red.
• Luster: Metallic, Glassy.
• Fracture: Conchoidal to Irregular.
• Tenacity: Fragile.
• Hardness (H): 3.0
• Streak: Gray to Black.
• Diaphaneity: Opaque.

Sphalerite (Blende) ($ ext{ZnS}$)

• Chemical Formula: $ ext{ZnS}$
• Crystal System: Cubic Crystals.
• Habit: Coarsely to Fine Grained.
• Color: Yellowish Brown.
• Luster: Resinous, Submetallic.
• Fracture: Conchoidal.
• Tenacity: Fragile.
• Hardness (H): 3.5 – 4.0
• Streak: Yellowish Brown.
• Diaphaneity: Translucent.

Chalcopyrite ($ ext{CuFeS}_2$)

• Chemical Formula: $ ext{CuFeS}_2$
• Crystal System: Tetragonal (often described as Tetrahedral habit).
• Color: Yellow Brass.
• Luster: Metallic.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 3.5 – 4.0
• Streak: Green.
• Diaphaneity: Opaque.

Galena ($ ext{PbS}$)

• Chemical Formula: $ ext{PbS}$
• Crystal System: Cubic.
• Color: Metallic Lead Gray.
• Luster: Metallic.
• Fracture: Smooth, Subconchoidal.
• Tenacity: Fragile.
• Hardness (H): 2.0
• Streak: Gray (Note: The text mentions '5 Gris', likely a specific gravity reference).
• Diaphaneity: Opaque.

Cinnabar ($ ext{HgS}$)

• Chemical Formula: $ ext{HgS}$
• Habit: Dark, Irregular, Tabular.
• Color: Red Chestnut.
• Luster: Adamantine to Matte.
• Fracture: Subconchoidal.
• Tenacity: Fragile.
• Hardness (H): 2.0
• Streak: Scarlet.
• Diaphaneity: Translucent.

Stibnite ($ ext{Sb}_2 ext{S}_3$)

• Chemical Formula: $ ext{Sb}_2 ext{S}_3$
• Habit: Acicular, Prismatic Crystals.
• Color: Blue Metallic Gray.
• Luster: Metallic.
• Fracture: Conchoidal.
• Tenacity: Flexible.
• Hardness (H): 2.0
• Streak: Gray.
• Diaphaneity: Opaque.

Pyrite ($ ext{FeS}_2$)

• Chemical Formula: $ ext{FeS}_2$
• Crystal System: Cubic Crystals.
• Color: Pale Yellow.
• Luster: Metallic.
• Fracture: Conchoidal to Irregular.
• Tenacity: Fragile.
• Hardness (H): 6.0 – 6.5
• Streak: Black.
• Diaphaneity: Opaque.

Molybdenite ($ ext{MoS}_2$)

• Chemical Formula: $ ext{MoS}_2$
• Habit: Hexagonal Crystals, Laminar.
• Color: Gray with Blue Reflections (Lead Gray).
• Luster: Metallic.
• Fracture: Irregular.
• Tenacity: Flexible.
• Hardness (H): 1.0 – 1.5
• Streak: Grayish Black.
• Diaphaneity: Opaque.

Tetrahedrite/Tennantite Series

Tetrahedrite ($ ext{Cu}_{12} ext{Sb}_4 ext{S}_{13}$) and Tennantite ($ ext{Cu}_{12} ext{As}_4 ext{S}_{13}$)

• Chemical Formula: $ ext{Cu}_{12} ext{Sb}_4 ext{S}_{13}$ (Tetrahedrite); $ ext{Cu}_{12} ext{As}_4 ext{S}_{13}$ (Tennantite).
• Habit: Usually Tetrahedral Mass, Granular, sometimes in cubes or dodecahedra.
• Color: Gray Black, often with a Blue Patina.
• Luster: Metallic.
• Fracture: Subconchoidal to Irregular.
• Tenacity: Fragile.
• Hardness (H): 3.0 – 4.5
• Streak: Reddish Brown to Black.
• Diaphaneity: Opaque.

Enargite ($ ext{Cu}_3 ext{AsS}_4$)

• Chemical Formula: $ ext{Cu}_3 ext{AsS}_4$
• Habit: Tabular or Prismatic Crystals, Granular Masses.
• Color: Iron Gray to Black, with a Grayish Patina.
• Luster: Metallic.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 3.0
• Streak: Gray to Black.
• Diaphaneity: Opaque, Matte.

Proustite ($ ext{Ag}_3 ext{AsS}_3$)

• Chemical Formula: $ ext{Ag}_3 ext{AsS}_3$
• Habit: Prismatic Crystals.
• Color: Vermilion Red.
• Luster: Adamantine.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 2.0 – 2.5
• Streak: Vermilion.
• Diaphaneity: Translucent.

Pyrargyrite ($ ext{Ag}_3 ext{SbS}_3$)

• Chemical Formula: $ ext{Ag}_3 ext{SbS}_3$
• Habit: Prismatic Crystals.
• Color: Intense Red (Ruby Silver).
• Luster: Adamantine.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 2.0
• Streak: Intense Red (Violaceous).
• Diaphaneity: Translucent.

Arsenopyrite ($ ext{FeAsS}$)

• Chemical Formula: $ ext{FeAsS}$
• Habit: Prismatic Crystals, Columnar.
• Color: Steel Gray (Acerado).
• Luster: Metallic.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 5.0 – 6.0
• Streak: Dark Blackish Gray.
• Diaphaneity: Opaque.

Pyrrhotite ($ ext{Fe}_{1-x} ext{S}$)

• Chemical Formula: $ ext{Fe}_{1-x} ext{S}$
• Habit: Hexagonal, Laminar.
• Color: Bronze Brown.
• Luster: Metallic.
• Fracture: Irregular.
• Tenacity: Fragile.
• Hardness (H): 4.0
• Streak: Black.
• Diaphaneity: Opaque.