Metamorphic Or Igneous (Context Dependent)

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Weathered granite (likely with accessory quartz)

Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende

Botryoidal chrysocolla with malachite

Chrysocolla (hydrated copper aluminosilicate) with malachite (Cu₂CO₃(OH)₂), possibly quartz/matrix

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper phyllosilicate; commonly approximated Cu₂H₂Si₂O₅(OH)₄·nH₂O), with possible malachite/limonite matrix

Tumbled red jasper or carnelian

Microcrystalline quartz (SiO₂), likely iron-rich jasper/chalcedony

Weathered iron-rich rock, possibly laterite or limonite-bearing stone

Hydrated iron oxides/hydroxides, chiefly limonite-goethite mixture; exact identification requires testing

Uncertain fine-grained rock or mineral-bearing specimen

Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains

Unidentified dark, flat specimen

Indeterminate; image resolution is insufficient for mineral identification

Rose Quartz

Silicon Dioxide (SiO2) containing trace amounts of titanium, iron, or manganese

Quartz with Mafic/Chlorite Veins

Silicon Dioxide (SiO2) with Chlorite/Epidote cross-veining

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Quartz with Pyrite

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Diamond

C (Carbon)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Tumbled green aventurine (probable)

Quartzite dominated by quartz (SiO₂), with green fuchsite mica inclusions

Emerald

Beryl (Be₃Al₂(SiO₃)₆) with Chromium or Vanadium impurities

Kidney Stone (Medical Specimen)

Calcium oxalate monohydrate (Whewellite) / CaC2O4·H2O

Botryoidal hematite (ironstone)

Hematite, Fe₂O₃

Polished chalcedony (likely moss/plume agate)

Microcrystalline quartz, SiO₂; chalcedony with possible iron-oxide inclusions

Tumbled chalcedony (likely gray/brown agate)

Microcrystalline quartz, SiO₂ (chalcedony; possible agate variety)

Yellow Sapphire

Corundum (Al2O3:Fe)

Diamond and Sapphire

Carbon (Diamond, C) and Aluminum Oxide (Sapphire, Al2O3)

Blue Sapphire

Corundum (Al2O3 with trace Titanium/Iron)

Quartz pebble

Silicon dioxide (SiO2)

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Kidney Stone

Calcium Oxalate (CaC2O4), Uric Acid, or Struvite

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) with host rock (often Schist or Basalt)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz with Iron Staining)

Silicon Dioxide (SiO2)

Auriferous Quartz or Pyritic Ore

Iron Pyrite (FeS2) or Native Gold (Au) in Matrix

Polished brecciated jasper

Jasper, an opaque microcrystalline quartz variety; primarily SiO₂ with iron-oxide and clay inclusions

Weathered pale-blue rock fragment

Unidentified; the image does not show enough detail for a reliable geological identification

Unidentified small rock or mineral fragment

Indeterminate from the blurred image; possibly quartz-rich stone, feldspar, or weathered concrete-like geological material

Milky Quartz with Chlorite/Moss Infusions

Silicon Dioxide (SiO2)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Blue faceted gemstone, likely synthetic sapphire or blue spinel

Corundum (Al₂O₃) if sapphire; alternatively magnesium aluminate spinel (MgAl₂O₄)

Ruby (Pink to Red Corundum)

Al2O3 (Corundum with Chromium impurities)

Granite

Granite (a common type of Felsic Intrusive Igneous Rock)

Pyrite on Quartz

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Milky Quartz

Silicon Dioxide (SiO2)