Opaque Minerals

• Name of mineral [chemical composition]
  1. Colours
  2. # Mohs' scale of hardness; Type of crystals
  3. Uses

• Acanthite (See: Argentite)
• Antimony [Native antimony]
  1. Silver-white
  2. # 3-3.5; Trigonal
  3. Research, collections
• Argentite [Silver sulfide]
  1. Lead-grey
  2. # 2-2.5; Cubic
  3. Source of silver
• Arsenic [Native arsenic]
  1. White, grey
  2. # 3-3.5; Trigonal
  3. No industrial use
• Arsenopyrite [Iron arsenic sulfide]
  1. Tin-white, steel-grey
  2. # 5.5-6; Monoclinic
  3. Source of arsenic, source of gold, silver, tin, cobalt as by-products
• Bismuthite [Bismuth sulfide]
  1. Lead-grey, tin-white, dull yellow
  2. # 2; Orthorhombic
  3. Source of bismuth
• Bornite [Copper iron sulfide]
  1. Red, bronze
  2. # 3; Cubic
  3. Source of copper
• Bournonite [Lead copper antimony sulfide]
  1. Grey, iron-black
  2. # 2.5-3; Orthorhombic
  3. Minor source of lead, copper, antimony
• Chalcocite [Copper sulfide]
  1. Lead-grey, black with blue reflections
  2. # 2.5-3; Orthorhomic
  3. Source of copper
• Chalcopyrite [Copper iron sulfide]
  1. Brass-yellow with green tones
  2. # 3.5-4; Tetragonal
  3. Source of copper; source of gold and silver as by-products
• Chromite [Iron chromate]
  1. Grey, grey-black, steel
  2. # 5.5; Monoclinic
  3. Minor source of copper
• Cobaltite [Cobalt sulfarsenide]
  1. White-grey with rose
  2. # 5.5; Orthorhombic
  3. Research, collections
• Columbite [Niobium iron oxide]
  1. Iron-black, black-brown
  2. # 6; Orthorhombic
  3. Source of niobium, tantalum; metallurgic industry, high-technology apparatus
• Copper [Native copper]
  1. Copper-red
  2. # 2.5-3; Cubic
  3. Electronics industry, manufacture of alloys
• Covellite [Copper sulfide]
  1. Indigo blue
  2. # 1.5-2; Hexagonal
  3. Source of copper
• Enargite [Copper arsenic sulfide]
  1. Grey, iron-black
  2. # 3; Orthorhombic
  3. Source of copper and arsenic
• Galena [Lead sulfide]
  1. Lead-grey
  2. # 2.5; Cubic
  3. Source of lead, source of silver as by-product
• Geocronite [Lead antimony sulfide]
  1. Lead-grey to blue-grey
  2. # 2.5; Monoclinic
  3. Research, collections
• Goethite [Hydrous ferrous oxide]
  1. Grey-black, brown-red, bright yellow
  2. # 5-5.5; Orthorhombic
  3. Source of iron; yellow dyes
• Glaucodot [Iron cobalt arsenic sulfide]
  1. Tin-white, light grey
  2. # 5; Monoclinic
  3. Source of cobalt
• Gold [Native gold]
  1. Golden yellow
  2. # 2.5-3; Cubic
  3. Jewelry, coins, dental technology, electronic and scientifc equipment
• Name of Stone: Graphite [Native carbon]
  1. Dark grey, lead-grey
  2. # 1-2; Hexagonal
  3. Electronics, dyestuffs, refractories, industries; dry lubricant, lead for pencils
• Hauerite [Manganese sulfide]
  1. Chestnut-brown to blackish
  2. # 4; Cubic
  3. Research, collections
• Hematite [Iron oxide]
  1. Brown, red, iron-grey blue, green
  2. # 5-6; Trigonal
  3. Source of iron; pigment
• Ilmenite [Titanium iron oxide]
  1. Iron-black, black-red
  2. # 5-6; Trigonal
  3. Source of titanium
• Jamesonite [Lead iron antimony sulfide]
  1. Grey-black
  2. # 2.5; Monoclinic
  3. Minor source of lead
• Magnetite [Iron oxide]
  1. Black, iron-grey
  2. # 5.5-6.5; Cubic
  3. Source of iron
• Markasite [Iron sulfide]
  1. Golden yellow, brass-yellow
  2. # 6-6.5; Orthorhombic
  3. Production of sulfuric acid, costume jewelry in the past
• Mercury [Native mercury]
  1. Silver-white
  2. Liquid at normal temperatures; Trigonal when solidified
  3. Extraction of gold and silver formerly, electrotechnology, fungicides formerly
• Millerite [Nickel sulfide]
  1. Brassy-yellow to bronze
  2. # 3-3.5; Trigonal
  3. Minor source of nickel
• Molybdenite [Molybdenum sulfide]
  1. Lead-grey
  2. # 1-1.5; Hexagonal
  3. Source of molybdenum; special alloys, dry lubricant
• Niccolite [Nickel arsenide]
  1. Copper-red with light green
  2. # 5-5.5; Hexagonal
  3. Source of nickel
• Platinum [Native platinum]
  1. Silvery-grey
  2. # 4-4.5; Cubic
  3. Jewelry, catalyst, high-technology equipment
• Pyrite [Iron sulfide]
  1. Brass-yellow, golden yellow
  2. # 6-6.5; Cubic
  3. Production of sulfuric acid; source of gold, copper, nickel, iron as by products
• Pyrolusite [Manganese oxide]
  1. Iron-black, dark grey
  2. # 6-6.5; Tetragonal
  3. Source of manganese; iron industry, glassworks
• Pyrrhotite [Iron sulfide]
  1. Bronze to red
  2. # 3.5-4.5; Hexagonal
  3. Minor source of lead
• Silver [Native silver]
  1. Silvery white
  2. # 2.5-3; Cubic
  3. Chemical and electronics industries, jewelry, coins
• Skutterudite [Cobalt arsenide]
  1. Tin-white, steel grey
  2. # 5.5-6; Cubic
  3. Source of cobalt, arsenic, nickel
• Stilnite [Antimony sulfide]
  1. Lead-grey with red or yellow
  2. # 2; Orthorhombic
  3. Source of antimony; alloys, fireworks, electric batteries
• Sylvanite [Gold silver telluride]
  1. Light yellow
  2. # 1.5-2; Monoclinic
  3. Source of gold, silver, tellurium
• Tenorite [Copper oxide]
  1. Black, iron-grey, steel
  2. # 3.5; Monoclinic
  3. Minor source of copper
• Tetrahedrite [Copper sulfantimonide]
  1. Steel-black, iron-grey
  2. # 3-4.5; Cubic
  3. Source of copper, also of silver, mercury, and antimony
• Uraninite [Uranium oxide]
  1. Black, grey, green, chestnut-brown
  2. # 5-6; Cubic
  3. Source of uranium; in nuclear reactors; source of radium as a by-product

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