Sedimentary (If Limestone) Or Metamorphic (If Marble)

Blue Calcite

Calcium Carbonate (CaCO3)

Weathered quartz-rich rock, likely quartzite or silicified limestone

Quartzite (mostly SiO₂), possibly calcareous quartzite with residual calcite

Weathered quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂), possibly with feldspar, mica, and iron-oxide staining

Quartzite River Pebble

Quartzite (primarily SiO2)

Banded calcite (possibly Iceland spar)

Calcite, CaCO₃

Yellow Calcite

Calcium Carbonate (CaCO3)

Rounded pale pebble, likely limestone

Calcite-rich limestone (CaCO₃), identification tentative from appearance

Likely calcite fragment

Calcite (CaCO₃), possibly limestone or marble

Quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline silicon dioxide (SiO₂)

Quartzite (River Pebble)

Metamorphosed Quartz Sandstone (primarily SiO2)

Yellow calcite (honey calcite)

Calcite, CaCO₃

Small rounded limestone pebble

Limestone, predominantly calcite (CaCO₃), possibly fossiliferous or oolitic

Green Calcite

Calcium Carbonate (CaCO3)

Ruby

Corundum (Al2O3 with Chromium traces)

Calcite with iron staining

Calcium Carbonate (CaCO3)

Travertine (likely polished limestone)

Calcite-rich carbonate rock; predominantly CaCO₃

Calcite-rich limestone, possibly fossiliferous

Limestone composed mainly of calcite (CaCO₃), potentially containing a fragmentary fossil or calcite-filled structure

Yellow Calcite

Calcium Carbonate (CaCO3)

Grey Quartzite Pebble

Quartzite (primarily SiO2 - Silicon Dioxide)

Lapis Lazuli

Lazurite cluster (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Rounded limestone pebble

Micritic limestone, primarily calcite (CaCO₃)

Calcite-rich limestone (possibly crystalline limestone)

Calcite, CaCO₃, in limestone; locally recrystallized toward marble

Yellow Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite

Calcium Carbonate (CaCO3)

Quartzite with Quartz Veining

Quartzite (primarily SiO2)

Lapis Lazuli

Lapis Lazuli (Complex rock containing Sodalite, Lazurite, Calcite, and Pyrite)

Lapis Lazuli (Tumbled Stone)

Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (predominantly Lazurite)

Lapis Lazuli

Complex mixture containing Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite

Lapis Lazuli

Lapis Lazuli (Complex aggregate mainly of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli (Low Grade)

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2)

Lapis Lazuli

Na6Ca2(Al6Si6O24)(SO4,S,Cl,OH)2 (Lazurite-dominated rock)

Honey Calcite

Calcite (Calcium Carbonate - CaCO3)

Limestone (likely weathered or plaster-coated)

Calcite-rich carbonate rock; primarily CaCO₃

Tumbled yellow-orange calcite

Calcite (CaCO₃), likely honey or orange calcite

Lapis lazuli

Lazurite-bearing calcite marble; typically lazurite (Na₃CaSi₃Al₃O₁₂S), calcite, pyrite

Likely calcite or quartz fragment

Uncertain from image; calcite (CaCO₃) is the leading possibility, with quartz (SiO₂) another possibility

Green Calcite

Calcium Carbonate (CaCO3)

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Honey Calcite

Calcium Carbonate (CaCO3)

Orange Calcite (Iron-Stained)

Calcium Carbonate (CaCO3)

Weathered limestone slab

Micritic limestone, primarily calcite (CaCO₃)