Organic Gemstone (Often Associated With Sedimentary Sequences)

Anthracite Coal

Anthracite (Carbon-based organic sedimentary/metamorphic rock)

Chert (specifically Iron-stained or Jasperoid Chert)

Microcrystalline Quartz (SiO2)

Anthracite Coal

Anthracite

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

Chert Pebble

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (variations include Flint/Jasper)

Chert (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Gold Nugget

Native Gold (Au)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Gold Nugget

Native Gold (Au)

Fuchsite (Green Muscovite)

K(Al,Cr)2(AlSi3O10)(OH)2

Lepidolite in Quartz (Obelisk)

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lepidolite)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chalcedony (Botryoidal Agate)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (SiO2)

Chert (Arrowhead variety)

Chert (SiO2)

Unakite

Epidotized Granite

Chert / Flint

Microcrystalline or cryptocrystalline quartz (SiO2)

Pyrite in Shale

Iron Disulfide (FeS2) in Sedimentary Shale

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

Diamond in Kimberlite

Kimberlite host rock with C (Carbon) inclusion

Fossiliferous Limestone with Rugose Coral

Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)

Chert (specifically Blue or Grey Chert/Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Aquamarine with Sunstone

Aquamarine (Be3Al2Si6O18), Sunstone (Na,Ca)Al(Si,Al)Si2O8

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Biogenic Inclusions

Fossil Coral (Honeycomb Coral)

Favosites (extinct genus of Tabulate coral)

Red Jasper (Chert)

Silicon Dioxide (SiO2)

Fossilized Gastropod (Snail)

Class Gastropoda (internal mold or 'steinkern')

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Tiger's Eye

Tiger's Eye (a variety of Quartz, SiO₂)

Chert (varietal Flint or Jasper)

Microcrystalline Quartz (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert / Flint (with quartz or calcite inclusion)

Silicon dioxide (SiO2)

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Moonstone

Adularia (orthoclase) or Albite (plagioclase), a potassium aluminum silicate of the feldspar group

Chert (Black Chert/Flint)

Cryptocrystalline Quartz (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Arsenopyrite in Quartz Matrix

Arsenopyrite (FeAsS) with Quartz (SiO2)

Chert (Quartz)

Microcrystalline Silica (SiO2)

Chert (with Quartz veins)

Microcrystalline quartz (SiO2)

Chert (Quartz Variety)

Chert (Silicon Dioxide, SiO2)