Organic Gemstone (Sedimentary Classification)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Amber (Copal)

Fossilized Tree Resin

Rounded gray-brown cobble, likely weathered sandstone or quartzite

Tentatively quartz-rich sandstone (SiO₂-dominated); exact identification requires hardness and acid tests

Ammonite fossil

Fossilized ammonoid cephalopod; likely an involute ammonite, exact genus/species indeterminate

Weathered quartz-rich rock, likely arkose or quartzite

Quartz-dominant siliciclastic rock; probable arkose (quartz + feldspar), possibly weakly metamorphosed quartzite

Dark metamorphic rock, likely hornfels or fine-grained basalt

Probable hornfels; commonly quartz–feldspar–mica with variable amphibole/pyroxene

Quartz-rich rock fragment, possibly chert or weathered quartz

Microcrystalline quartz (SiO₂), tentative identification

Granite (likely biotite granite)

Coarse-grained granitic rock; chiefly quartz, potassium feldspar, plagioclase, and biotite/hornblende

Quartz-rich chalcedony (likely silicified rock)

Microcrystalline quartz, SiO₂; possibly silicified limestone or jasper

Greenschist

Greenschist (containing Chlorite, Epidote, and Actinolite)

Amber

Organic gemstone (Succinite)

Script Jasper

Silicon Dioxide (SiO2) with impurities

Lunar Highlands Breccia (Meteorite)

Lunar Feldspathic Breccia

Martian Meteorite (Black Beauty)

Martian (basaltic breccia) Meteorite, Northwest Africa (NWA) 7034

Lunar Feldspathic Breccia

Lunar Meteorite (Feldspathic Regolith Breccia)

Weathered sandstone or quartzite cobble

Quartz-rich sandstone; possibly weakly metamorphosed quartzite

Tumbled Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide

Weathered quartz-rich rock, possibly quartzite or granite fragment

Quartzite (SiO₂-dominant) or altered granitoid; uncertain from image

Red jasper pebble

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Mixed tumbled stones

Mixed mineral specimens; visible pieces may include quartz, feldspar, calcite, and other silicates

Likely iron-rich meteorite fragment

Unclassified iron oxide–rich meteorite; composition cannot be confirmed visually

Amber

Succinite (a fossilized organic resin)

Granite countertop slab

Granite; primarily quartz, feldspar, and mica (commonly biotite), with accessory amphibole/iron oxides

Bamboo Leaf Jasper

Silicified Siltstone or Jasper (SiO2)

Jasper

Microcrystalline quartz (SiO2)

Rounded river cobble, likely weathered sandstone or quartz-rich metasandstone

Indeterminate sandstone; commonly quartz (SiO₂) with feldspar, lithic grains, and iron-oxide cement

Chondrite Meteorite

L or H Ordinary Chondrite

Dalmatian jasper (likely orbicular microgranite)

Quartz–feldspar–biotite/pyroxene microgranite; commonly marketed as Dalmatian jasper

Polished yellow-brown jasper

Jasper, a microcrystalline variety of quartz (SiO₂), commonly containing iron-oxide impurities

Polished amber

Amber (fossilized plant resin; chiefly amorphous organic compounds)

Tiger’s eye

Quartz variety, primarily silicon dioxide (SiO₂); fibrous quartz pseudomorph after crocidolite asbestos

Amber (in Matrix/Shale)

Amber (Fossilized Tree Resin)

Red Coral (Precious Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Dalmatian jasper (often sold as Dalmatian stone)

Porphyritic alkali feldspar–quartz syenite, commonly with black arfvedsonite/aegirine-group amphibole inclusions

Granite (likely weathered granite or granitic gneiss)

Granite; primarily quartz (SiO₂), feldspar, and mica (biotite/muscovite)

Greenschist

Chlorite Schist

Yellow-green serpentine (likely)

Serpentine-group phyllosilicate, commonly lizardite or antigorite; approximate formula Mg₃Si₂O₅(OH)₄

Amber

Succinite (Organic Gemstone)

Green sea glass (likely)

Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock

Amber

Succinite (organic gemstone, approx. C10H16O)

Banded Chert

Microcrystalline Quartz (SiO2)

Quartz-rich granite or granitic pegmatite

Granite; chiefly quartz (SiO₂), potassium feldspar and plagioclase, with minor mica/iron oxides