Sedimentary (Chemically Precipitated) Or Metamorphic

Jasper (with orbicular/unakitoid tendencies)

Silicon Dioxide (SiO2) with iron and epidote inclusions

Weathered quartz-rich rock, possibly chert or quartzite

Indeterminate; likely microcrystalline quartz (SiO₂), possibly quartzite or chert

Jasper

Microcrystalline Quartz (SiO2)

Bumblebee Jasper

Travertine (Calcite/Aragonite) with Realgar, Pyrite, and Volcanic Ash

Quartz fragment

Silicon Dioxide (SiO2)

Reddish quartz-rich rock, possibly jasper or chert

Microcrystalline quartz (SiO₂), likely iron-oxide-stained jasper/chert

Chert (Jasper/Jasperoid)

Chert (chemically precipitated microcrystalline Quartz, SiO2)

Iron-rich chert or jasper

Microcrystalline quartz (SiO₂), likely hematite/goethite-bearing

Quartz-rich metamorphic rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite composed predominantly of recrystallized quartz

Quartz vein rock (milky quartz)

Milky quartz, SiO₂; likely quartz-rich vein material in altered host rock

Quartz (Milky/Crystalline fragment)

Silicon Dioxide (SiO2)

Chert

Chert (Microcrystalline Quartz, SiO2)

Weathered iron-rich rock, possibly ironstone or altered basalt

Indeterminate; likely ferruginous basalt/ironstone containing hematite-goethite and silicate minerals

Banded iron formation (iron-rich metamorphic rock)

BIF; alternating chert/quartz and hematite–magnetite layers

Yellow Calcite

Calcium Carbonate, CaCO3

White quartz cluster

Quartz (silicon dioxide, SiO₂), likely a drusy or microcrystalline cluster

Orange Calcite

Calcium Carbonate (CaCO3)

Onyx Marble (Banded Calcite)

Calcite (Calcium Carbonate, CaCO3)

Tumbled iron-rich chert or jasper

Microcrystalline quartz (SiO₂), likely limonitic/hematitic variety

Weathered limestone fragment

Calcite-rich limestone (CaCO₃), possibly fossiliferous or brecciated

Orange Calcite

Calcium Carbonate (CaCO3)

Weathered limestone pebble

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

Likely calcite-bearing limestone

Calcite (CaCO₃), probably in a porous limestone fragment

Orange Calcite

Calcium Carbonate (CaCO3)

Weathered limestone

Micritic limestone, primarily calcite (CaCO₃)

Likely limestone fragment

Calcite-rich carbonate rock; primarily calcium carbonate (CaCO₃)

Chert (Iron-Stained)

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3) impurities

Iceland Spar (Optical Calcite)

Calcite (CaCO3)

Calcite

Calcium Carbonate (CaCO3)

Calcite

Calcium Carbonate (CaCO3)

Red Jasper Pebble

Microcrystalline Quartz (SiO2)

Banded jasper / iron-rich chert (probable)

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides and clay minerals

Blue Calcite

Calcium Carbonate (CaCO3)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Blue Calcite

Calcium Carbonate (CaCO3)

Calcite

Calcium Carbonate (CaCO3)

Calcite (with iron oxide staining)

Calcium Carbonate (CaCO3)

Turquoise

Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O

Quartz Vein in Sandstone

Hydrothermal Quartz (SiO2) in Arenite

Weathered chert or siliceous limestone

Microcrystalline quartz (SiO₂), possibly replacing or cementing carbonate rock