Crystals
Tektite
Tektite • natural terrestrial glass launched from an impact site and deposited across a strewn field Formed during hypervelocity meteorite or asteroid impacts Amorphous glass • no crystal system or...
Tektite
Tektite • natural terrestrial glass launched from an impact site and deposited across a strewn field Formed during hypervelocity meteorite or asteroid impacts Amorphous glass • no crystal system or...
Stromatolite
Stromatolite • laminated microbialite built through repeated surface accretion Microbial mats trap, bind, stabilize, and mineralize sediment Planar, domal, columnar, branching, and conical forms Commonly carbonate; also silicified, dolomitized, phosphatic,...
Stromatolite
Stromatolite • laminated microbialite built through repeated surface accretion Microbial mats trap, bind, stabilize, and mineralize sediment Planar, domal, columnar, branching, and conical forms Commonly carbonate; also silicified, dolomitized, phosphatic,...
Shungite
Shungite • carbon-rich rock and natural solid carbonaceous matter No fixed mineral formula Onega Basin • Republic of Karelia Zaonega Formation • approximately 2.10–1.98 billion years old Disordered sp²-rich carbon...
Shungite
Shungite • carbon-rich rock and natural solid carbonaceous matter No fixed mineral formula Onega Basin • Republic of Karelia Zaonega Formation • approximately 2.10–1.98 billion years old Disordered sp²-rich carbon...
Shattuckite
Shattuckite • copper silicate hydroxide Formula: Cu5(SiO3)4(OH)2 Orthorhombic • fibrous, acicular, radial, felted, and massive Mohs about 3.5 • specific gravity about 3.8–4.1 Silky to dull luster • pale-blue streak...
Shattuckite
Shattuckite • copper silicate hydroxide Formula: Cu5(SiO3)4(OH)2 Orthorhombic • fibrous, acicular, radial, felted, and massive Mohs about 3.5 • specific gravity about 3.8–4.1 Silky to dull luster • pale-blue streak...
Ruby with zoisite
Ruby in Zoisite • natural metamorphic rock composed of contrasting mineral phases Ruby: chromium-bearing corundum, Al2O3 Green matrix: chromium-bearing zoisite, Ca2Al3(SiO4)(Si2O7)O(OH) Dark phase: commonly pargasite amphibole in classic Longido material...
Ruby with zoisite
Ruby in Zoisite • natural metamorphic rock composed of contrasting mineral phases Ruby: chromium-bearing corundum, Al2O3 Green matrix: chromium-bearing zoisite, Ca2Al3(SiO4)(Si2O7)O(OH) Dark phase: commonly pargasite amphibole in classic Longido material...
Sunstone
Sunstone • gem and trade name for feldspar displaying warm color, metallic inclusions, or aventurescent schiller Most classic material: plagioclase feldspar Some sunstone is orthoclase or microcline Mohs about 6–6.5...
Sunstone
Sunstone • gem and trade name for feldspar displaying warm color, metallic inclusions, or aventurescent schiller Most classic material: plagioclase feldspar Some sunstone is orthoclase or microcline Mohs about 6–6.5...