Crystals
Rose quartz
Pink gem variety of quartz SiO2 Classic material is massive and usually translucent Color from aligned dumortierite-related silicate nanofibers Rare euhedral pink quartz has a different color-center mechanism Trigonal α-quartz...
Rose quartz
Pink gem variety of quartz SiO2 Classic material is massive and usually translucent Color from aligned dumortierite-related silicate nanofibers Rare euhedral pink quartz has a different color-center mechanism Trigonal α-quartz...
Red jasper
Opaque microcrystalline silica-rich stone Red color dominated by finely dispersed hematite No rock-wide cleavage; conchoidal to uneven fracture Mohs approximately 6.5–7 Massive, ribboned, brecciated, scenic, and orbicular patterns Widely distributed...
Red jasper
Opaque microcrystalline silica-rich stone Red color dominated by finely dispersed hematite No rock-wide cleavage; conchoidal to uneven fracture Mohs approximately 6.5–7 Massive, ribboned, brecciated, scenic, and orbicular patterns Widely distributed...
Smoky quartz
Macrocrystalline quartz, SiO2 Brown color from irradiation-activated aluminum defects Mohs 7, specific gravity approximately 2.65 Trigonal, uniaxial positive, no cleavage Cairngorm, morion, phantoms, scepters, and gwindels “Smoky topaz” is an...
Smoky quartz
Macrocrystalline quartz, SiO2 Brown color from irradiation-activated aluminum defects Mohs 7, specific gravity approximately 2.65 Trigonal, uniaxial positive, no cleavage Cairngorm, morion, phantoms, scepters, and gwindels “Smoky topaz” is an...
Snakeskin jasper
Trade-named jaspilite and banded iron formation Red iron-rich bands with pale chert laminae Classic source: Turee Creek, Pilbara, Western Australia Formation age approximately 2.45 billion years Folds, microbands, scale-like cells,...
Snakeskin jasper
Trade-named jaspilite and banded iron formation Red iron-rich bands with pale chert laminae Classic source: Turee Creek, Pilbara, Western Australia Formation age approximately 2.45 billion years Folds, microbands, scale-like cells,...
Apache tear
Rounded nodules of natural obsidian Silica-rich rhyolitic volcanic glass Amorphous rather than crystalline Mohs approximately 5–5.5 Warm brown translucency in strong backlight Conchoidal fracture and exceptionally sharp fresh edges Apache...
Apache tear
Rounded nodules of natural obsidian Silica-rich rhyolitic volcanic glass Amorphous rather than crystalline Mohs approximately 5–5.5 Warm brown translucency in strong backlight Conchoidal fracture and exceptionally sharp fresh edges Apache...
Lapis lazuli
Lazurite-rich metamorphic rock (Na,Ca)8(AlSiO4)6(S,SO4,Cl)2 Sodalite-group framework Bulk hardness commonly about 5–5.5 Brassy pyrite inclusions White calcite veins and clouds Ultramarine from sulfur radical anions Historic source: Badakhshan, Afghanistan Lapis Lazuli:...
Lapis lazuli
Lazurite-rich metamorphic rock (Na,Ca)8(AlSiO4)6(S,SO4,Cl)2 Sodalite-group framework Bulk hardness commonly about 5–5.5 Brassy pyrite inclusions White calcite veins and clouds Ultramarine from sulfur radical anions Historic source: Badakhshan, Afghanistan Lapis Lazuli:...