Organic Gem Material (Botanical)

White Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Rhodonite

Rhodonite ((Mn2+,Fe2+,Mg,Ca)SiO3)

Amethyst quartz fragment

Quartz, silicon dioxide (SiO₂), purple variety colored primarily by iron impurities and irradiation

Peridotite (Pyroxenite/Serpentinized Dunite)

Ultramafic Rock (consisting primarily of Olivine and Pyroxene)

Likely garnet-bearing schist or weathered garnet amphibolite

Garnet (almandine, Fe₃Al₂Si₃O₁₂) in a mica-rich metamorphic matrix

Chert (Flint)

Silicon dioxide (SiO2)

Moonstone cabochon ring

Adularia moonstone, potassium feldspar (orthoclase, KAlSi₃O₈), possibly imitation or another white translucent gemstone

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, commonly intergrown with white calcite

Iron-rich quartzite or iron-stained quartz

Quartzite; predominantly quartz (SiO₂) with iron-oxide/hydroxide coatings, possibly minor mica or feldspar

Light-colored tumbled stone, likely quartzite or marble

Quartzite (mostly SiO₂) or calcitic marble (CaCO₃); exact identification is uncertain from the image

Quartz–feldspar pegmatite with pink tourmaline

Granitic pegmatite; predominantly quartz (SiO₂), microcline/orthoclase (KAlSi₃O₈), albite (NaAlSi₃O₈), and likely elbaite tourmaline (Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Quartz vein in dark host rock

Quartz (SiO₂), likely within basalt, diabase, or another mafic volcanic rock

Milky quartz

Quartz (silicon dioxide, SiO₂)

Diamond

Diamond (pure carbon, C)

Diamond (faceted)

Carbon (C)

Chert (Jasper/Chalcedony mix)

Microcrystalline Quartz (SiO2)

Tumbled amethyst quartz

Quartz (SiO₂), purple variety amethyst

Yellow chalcedony (likely honey agate/jasper)

Microcrystalline quartz, SiO₂; may contain iron-oxide inclusions

Chert Nodule in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Black faceted gemstone, possibly black spinel or onyx

Undetermined; candidates include spinel (MgAl₂O₄) or chalcedony (SiO₂)

Tumbled amber-colored quartz or chalcedony

Microcrystalline quartz (SiO₂), possibly iron-stained chalcedony

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Peridot

Olivine (specific variety: gem-quality forsterite), (Mg,Fe)2SiO4

Rounded river cobble, likely basaltic volcanic rock

Fine-grained mafic igneous rock; likely basalt or andesite

Rounded quartz-rich river cobble (probable rhyolite/granite-derived stone)

Indeterminate felsic igneous cobble; likely quartz–feldspar aggregate with minor iron oxides

Possible industrial slag or basaltic volcanic glass

Likely iron-rich vitreous slag; natural alternative: basaltic glass (tachylite)

Oxidized iron-rich rock, possibly weathered basalt or ironstone

Likely ferruginous basalt or hematite/goethite-rich breccia; exact identification requires testing

Tumbled amethyst

Amethyst, purple quartz (SiO₂)

White quartz-rich rock, likely quartzite or silicified sediment

Quartzite (mostly quartz, SiO₂); possibly silicified limestone or chert

Polished amethyst or quartz chip

Quartz, silicon dioxide (SiO₂), likely purple amethyst with possible iron-oxide inclusions

Cut faceted gemstone, possibly diamond or quartz

Uncertain from the blurred image; diamond is crystalline carbon (C), while quartz is silicon dioxide (SiO₂)

Gemstone Sand (Mineral Assortment)

Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

Rough Diamond

Diamond (C)

Likely weathered limestone

Calcite-rich limestone (mostly CaCO₃), possibly dolomitic limestone

Faceted yellow-brown gemstone ring

Likely citrine (quartz, SiO₂); the image alone cannot confirm the stone or any treatments.

Chert (Flint)

Silicon Dioxide (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Iridescent labradorite fragment

Labradorite, plagioclase feldspar: approximately An50–70

Milky quartz with iron-stained mica

Quartz (SiO₂), likely intergrown with muscovite and minor iron oxides

Chert Nodules in Limestone

Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)