Minerals: Native Elements
Minerals are defined by five criteria: 1. Naturally Occurring, 2. Inorganic, 3. Solid, 4. Defined Chemical (Atomic) Formula, and 5. A unique set of physical properties.
Native Elements – are free, uncombined elements what are classified into three groups: Metals such as gold, silver, and copper; semimetals such as arsenic and antimony; and non-metals, including carbon and sulfur.
Metals
Metallic elements are very dense, soft, malleable, ductile, and opaque. Massive dendritic, wire-like habits are common. Distinct crystals are rare.
Specimen: Gold band in Quartzite
Classification: Native Elements
Chemical Composition: Au
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 19.3
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in Hydrothermal veins in mountains and weathered in river channels.
Uses: Currencly, jewelrly, decoration.
Specimen: Gold flakes
Classification: Native Elements
Chemical Composition: Au
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 19.3
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in Hydrothermal veins in mountains and weathered in river channels.
Uses: Currencly, jewelrly, decoration.
Specimen: Native Silver flakes
Classification: Native Elements
Chemical Composition: Ag
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 10.5
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in hydrothermal veins in mountains and volcanoes
Uses: Currencly, jewelrly, utensils, decoration.
Specimen: Native Silver
Classification: Native Elements
Chemical Composition: Ag
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 10.5
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in hydrothermal veins in mountains and volcanoes
Uses: Currencly, jewelrly, utensils, decoration.
Specimen: Native Silver on quartz
Classification: Native Elements
Chemical Composition: Ag
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 10.5
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in hydrothermal veins in mountains and volcanoes
Uses: Currencly, jewelrly, utensils, decoration.
Specimen: Native Silver
Classification: Native Elements
Chemical Composition: Ag
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 10.5
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. Found in hydrothermal veins in mountains and volcanoes
Uses: Currencly, jewelrly, utensils, decoration.
Specimen: Native Copper
Classification: Native Elements
Chemical Composition: Cu
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 8.9
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. ound in hydrothermal veins in mountains.
Uses: Currencly (United States penny coating), jewelrly, utensils, decoration.
Specimen: Native Copper
Classification: Native Elements
Chemical Composition: Cu
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 8.9
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. ound in hydrothermal veins in mountains.
Uses: Currencly (United States penny coating), jewelrly, utensils, decoration.
Specimen: Native Copper (Oxidizing)
Classification: Native Elements
Chemical Composition: Cu
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 8.9
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. ound in hydrothermal veins in mountains.
Uses: Currencly (United States penny coating), jewelrly, utensils, decoration.
Specimen: Oxidized Native Copper
Classification: Native Elements
Chemical Composition: Cu
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 8.9
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. ound in hydrothermal veins in mountains.
Uses: Currencly (United States penny coating), jewelrly, utensils, decoration.
Specimen: Oxidized Native Copper
Classification: Native Elements
Chemical Composition: Cu
Crystal structure: Cubic
Hardness: 2.5 to 3
Specific Gravity: 8.9
Luster: Metallic
Cleavage: None
Fracture: Hackly
Source: Forms in exploding stars. ound in hydrothermal veins in mountains.
Uses: Currencly (United States penny coating), jewelrly, utensils, decoration.
Semimetals
Unilike metals, semimetals are poor conductors of electricity, and they usually occur in nodular masses.
Specimen: Native Bismuth
Classification: Native Elements
Chemical Composition: Bi
Crystal structure: Trigonal/Hexagonal
Hardness: 2 to 2.5
Specific Gravity: 9.7 to 9.8
Luster: Metallic
Cleavage: Perfect basal
Fracture: Uneven
Source: Hydrothermal veins and pegmatites
Uses: Collections
Specimen: Man-made Bismuth
Classification: Native Elements
Chemical Composition: Bi
Crystal structure: Trigonal/Hexagonal
Hardness: 2 to 2.5
Specific Gravity: 9.7 to 9.8
Luster: Metallic
Cleavage: Perfect basal
Fracture: Uneven
Source: Hydrothermal veins and pegmatites
Uses: Collections
Specimen: Man-made Bismuth
Classification: Native Elements
Chemical Composition: Bi
Crystal structure: Trigonal/Hexagonal
Hardness: 2 to 2.5
Specific Gravity: 9.7 to 9.8
Luster: Metallic
Cleavage: Perfect basal
Fracture: Uneven
Source: Hydrothermal veins and pegmatites
Uses: Collections
Specimen: Arsenic
Classification: Native Elements
Chemical Composition: As
Crystal structure: Trigonal/Hexagonal
Hardness: 3.5
Specific Gravity: 5.7
Luster: Metallic
Cleavage: Perfect basal
Fracture: Uneven
Source: Hydrothermal veins
Uses: Collections
Non-metals
Non-metallic elements are tranparent to translucent, do not conduct electricity, and tend to form distinct crystals.
Specimen: Native Sulfur
Classification: Native Elements
Chemical Composition: S
Crystal structure: Orthorhombic
Hardness: 1.5 to 2.5
Specific gravity: 2.0 to 2.1
Luster: Vitreous to resinous
Cleavage: Imperfect basal
Fracture: Uneven to conchoidal
Source: Forms around volcanic craters and hot springs.
Uses: Collections, matches, industrial uses.
Specimen: Native Sulfur
Classification: Native Elements
Chemical Composition: S
Crystal structure: Orthorhombic
Hardness: 1.5 to 2.5
Specific gravity: 2.0 to 2.1
Luster: Vitreous to resinous
Cleavage: Imperfect basal
Fracture: Uneven to conchoidal
Source: Forms around volcanic craters and hot springs.
Uses: Collections, matches, industrial uses.
Specimen: Native Sulfur
Classification: Native Elements
Chemical Composition: S
Crystal structure: Orthorhombic
Hardness: 1.5 to 2.5
Specific gravity: 2.0 to 2.1
Luster: Vitreous to resinous
Cleavage: Imperfect basal
Fracture: Uneven to conchoidal
Source: Forms around volcanic craters and hot springs.
Uses: Collections, matches, industrial uses.
Specimen: Native Rough Diamond
Classification: Native Elements
Chemical Composition: C
Crystal structure: Cubic
Hardness: 10
Specific gravity: 3.52
Luster: Vitreous
Cleavage: Perfect octahedral
Fracture: Conchoidal
Source: Forms in ultrabasic rocks (kimberlites), and pipelike intrustions.
Uses: Collections, jewelery, industiral grits and drillbits.
Specimen: Native Graphite
Classification: Native Elements
Chemical Composition: C
Crystal structure: Trigonal/Hexagonal
Hardness: 1 to 2
Specific gravity: 2.1 to 2.3
Luster: Sub-metallic
Cleavage: Perfect basal
Fracture: Uneven
Streak: Black to grey
Feel: Greasy
Source: Forms in metamorphic rocks including slate and schist
Uses: Industiral lubricant and pencils.
Specimen: Native Graphite
Classification: Native Elements
Chemical Composition: C
Crystal structure: Trigonal/Hexagonal
Hardness: 1 to 2
Specific gravity: 2.1 to 2.3
Luster: Sub-metallic
Cleavage: Perfect basal
Fracture: Uneven
Streak: Black to grey
Feel: Greasy
Source: Forms in metamorphic rocks including slate and schist
Uses: Industiral lubricant and pencils.
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Data: Pellant, Chris. Smithsonian Handbooks: Rocks and Minerals, The clearest recognition guides avaiable. A Dorling Kindersley Book.