Crystals
Seraphinite
Seraphinite • lapidary trade name for plume-patterned clinochlore Representative clinochlore formula: Mg5Al(AlSi3O10)(OH)8 Chlorite group • layered phyllosilicate Monoclinic • perfect basal cleavage Silvery plumes from aligned reflective lamellae Mohs about...
Seraphinite
Seraphinite • lapidary trade name for plume-patterned clinochlore Representative clinochlore formula: Mg5Al(AlSi3O10)(OH)8 Chlorite group • layered phyllosilicate Monoclinic • perfect basal cleavage Silvery plumes from aligned reflective lamellae Mohs about...
Turquoise
Turquoise • hydrated copper–aluminum phosphate CuAl6(PO4)4(OH)8·4H2O Triclinic • commonly compact, microcrystalline, and vein-forming Mohs about 5–6 • lower in porous or altered material Blue, blue-green, green, and yellow-green Copper supplies...
Turquoise
Turquoise • hydrated copper–aluminum phosphate CuAl6(PO4)4(OH)8·4H2O Triclinic • commonly compact, microcrystalline, and vein-forming Mohs about 5–6 • lower in porous or altered material Blue, blue-green, green, and yellow-green Copper supplies...
Tourmaline
Tourmaline supergroup • boron-bearing ring silicates XY3Z6(T6O18)(BO3)3V3W Trigonal • polar and commonly hemimorphic Long striated prisms • rounded-triangular cross sections Mohs 7–7.5 • specific gravity about 2.82–3.32 Strong pleochroism •...
Tourmaline
Tourmaline supergroup • boron-bearing ring silicates XY3Z6(T6O18)(BO3)3V3W Trigonal • polar and commonly hemimorphic Long striated prisms • rounded-triangular cross sections Mohs 7–7.5 • specific gravity about 2.82–3.32 Strong pleochroism •...
Flint
Dark variety of chert Predominantly SiO2 Microcrystalline silica rock Mohs approximately 6.5–7 Conchoidal fracture Nodules and layers in chalk or limestone Produces sparks against high-carbon steel Black, gray, brown, honey,...
Flint
Dark variety of chert Predominantly SiO2 Microcrystalline silica rock Mohs approximately 6.5–7 Conchoidal fracture Nodules and layers in chalk or limestone Produces sparks against high-carbon steel Black, gray, brown, honey,...
Kunzite
Kunzite • pink-to-violet gem variety of spodumene • LiAlSi2O6 Pyroxene group • monoclinic single-chain silicate Strong pleochroism • pale blush to saturated lilac by direction Perfect cleavage in two directions...
Kunzite
Kunzite • pink-to-violet gem variety of spodumene • LiAlSi2O6 Pyroxene group • monoclinic single-chain silicate Strong pleochroism • pale blush to saturated lilac by direction Perfect cleavage in two directions...
Iron tiger eye
Iron Tiger Eye • Tiger Iron • banded lapidary rock composed of chatoyant quartz, iron oxides, and red jasper Golden tiger-eye bands • aligned fibrous texture and moving reflected light...
Iron tiger eye
Iron Tiger Eye • Tiger Iron • banded lapidary rock composed of chatoyant quartz, iron oxides, and red jasper Golden tiger-eye bands • aligned fibrous texture and moving reflected light...