Organic Gem Material (Botanical)

Jasper

Microcrystalline quartz (SiO2)

Fossilized Shark Tooth (Partial) or Coprolite

Elasmobranchii (fossil) or Coprolite (trace fossil)

Graphite

Graphite (Carbon, C)

Nacre (Mother of Pearl)

Nacre (Biogenic Aragonite/Calcite composite, CaCO3)

Fossiliferous Flint

Microcrystalline Quartz (SiO2) with Echinoid Fossil

Likely dark rounded stone or mineral fragment

Indeterminate; possibly a water-worn mafic rock such as basalt

Rough Black Diamond (Bort / Carbonado)

Diamond (C)

Fossiliferous limestone, likely crinoidal limestone

Bioclastic limestone; predominantly calcite (CaCO₃), with possible dolomite and silicate impurities

Polished river pebble

Indeterminate; likely fine-grained quartz-rich sedimentary rock or weathered volcanic rock

Weathered basalt (possibly iron-stained volcanic rock)

Basalt; predominantly plagioclase, pyroxene, and possibly olivine, with iron-oxide staining

Dark igneous rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂), with minor iron-oxide and mica impurities

Pegmatitic rose quartz with black tourmaline

Quartz (SiO₂) with schorl tourmaline (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄), likely feldspar and mica

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Tumbled chalcedony (likely moss or dendritic agate)

Microcrystalline quartz, SiO₂, with iron-oxide inclusions

Opalite crescent pendant

Opalite (man-made opalescent glass; not a natural mineral)

Weathered iron-rich rock, possibly limonite-bearing sandstone or altered volcanic rock

Limonite/goethite mixture; exact host rock is indeterminate from the image

Tumbled brown chalcedony or jasper

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

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

Diamond

Carbon (C)

Weathered quartz-rich rock, likely quartzite or silicified sandstone

Quartzite; predominantly microcrystalline to granular SiO₂, possibly with iron-oxide impurities

Tumbled carnelian (orange chalcedony)

Carnelian, a microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Red sandstone boulder

Quartz-rich sandstone, commonly arkose or iron-oxide-cemented sandstone

Polished ruby-in-fuchsite (tentative)

Fuchsite mica with corundum (ruby), commonly in quartzite or mica schist

Rose quartz (likely)

Quartz, silicon dioxide (SiO₂), pink variety

Green tourmaline crystal (probable)

Elbaite tourmaline, complex borosilicate; approximate formula Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Amethyst (purple quartz)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Iron-stained quartz-rich rock, possibly quartzite or hydrothermal quartz

Quartz (SiO₂), likely with iron oxides; exact host rock uncertain from the photograph

Veined quartz-bearing metamorphic rock

Likely quartzite or siliceous schist with iron-oxide staining

Potassium-Rich Silicate Clay (inferred from biological context)

Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)

Diamond (faceted)

Carbon (C)

Amber

Succinite (C10H16O)

Polished malachite slab

Malachite, Cu₂CO₃(OH)₂; likely polished and possibly resin-stabilized

Porphyritic granite pebble

Granite, chiefly quartz (SiO₂), alkali feldspar and plagioclase, with minor biotite/hornblende

Petrified Wood

Silicified Wood (SiO2)

Fossilized Shell Fragment / Mother of Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral

Iron-stained quartz-rich rock fragments

Likely quartz (SiO₂) with limonite/goethite iron oxides; possibly quartzite or silicified rock

Uncut diamond (likely gemstone)

Diamond — crystalline carbon, C

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Feldspar)

Rough Ruby

Corundum (Al2O3) with Chromium traces

Quartz-rich iron-stained rock, likely quartzite or quartz vein material

Quartz (SiO₂), with iron oxides/hydroxides such as hematite and goethite

Smoky Quartz

Silicon Dioxide (SiO2)