Not A Rock (Synthetic Material)

Chalk

Calcareous Ooze (composed primarily of coccoliths)

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Soapstone

Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)

Chert (or Flint)

Chert (a cryptocrystalline variety of quartz, SiO2)

Agate

Agate (a variety of Chalcedony, SiO2)

Lapis Lazuli

Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)

Lapis Lazuli

Lapis Lazuli (a rock type, not a single mineral; main component is Lazurite (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)])

Red Tiger's Eye beads

Tiger's Eye (variety of Chalcedony, SiO2)

Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Pyrite

Pyrite (Iron Disulfide), FeS2

Quartzite

Quartzite (SiO2)

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Slate

Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Caliche (also known as hardpan, calcrete, kankar)

Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.

Diamond

Diamond (Carbon, C)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂)

Aventurine

Aventurine Quartz (SiO2 with inclusions)

Smoky Quartz

Silicon Dioxide (SiO2)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Emerald

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

Chert (Jasper-like)

SiO2 (Cryptocrystalline Quartz)

Obsidian

Obsidian (volcanic glass)

Quartz

Quartz (SiO₂)

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Emerald

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

Halite

Halite (NaCl)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Dolomite

Dolomite (CaMg(CO3)2)

Rose Quartz

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

Smoky Quartz

Silicon Dioxide (SiO2)

Quartz

Quartz (SiO₂)

Quartz

Silicon dioxide (SiO₂)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Shale

Shale

Banded Gneiss

Gneiss (typically quartz, feldspar, mica, amphibole composition)

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Smoky Quartz

Silicon Dioxide (SiO2)

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Quartz

Silicon Dioxide (SiO₂)