Mineral Based Human Made Alloy

Granite countertop with a small pale mineral fragment

Granite; predominantly quartz, feldspar, and mica

Tree Agate

Silicon dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Tumbled jasper, likely picture jasper or brecciated jasper

Microcrystalline quartz (SiO₂), chiefly chalcedony with iron-oxide pigments

Chert (often called Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert / Chalcedony

Microcrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint variant)

Cryptocrystalline Quartz (SiO2)

Asphalt Chunk (Bituminous Concrete)

Aggregated Bitumen / Artificial Breccia

Desert Rose (also known as Sand Rose)

Gypsum (CaSO4·2H2O) or Barite (BaSO4) with sand inclusions

Chert (specifically Gray/Tan Bedded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Nodular Chert)

Silicon Dioxide (SiO2)

Polished pink-and-white quartz bead bracelet

Quartz (SiO₂), likely rose quartz and milky quartz; some orange beads may be iron-stained quartz or pale carnelian

Tumbled milky quartz (probable)

Quartz, silicon dioxide (SiO₂)

Tumbled carnelian (likely chalcedony)

Carnelian, orange-red cryptocrystalline quartz (SiO₂), a variety of chalcedony

Chert (specifically Gray/Tan Chert Node)

Microcrystalline Quartz (SiO2)

Peridot (likely, based on color and appearance)

Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)

Diamond

Carbon (C)

Diamond

Carbon (C)

Rough Diamond

Diamond (pure Carbon, C)

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

Obsidian

Obsidian (Volcanic Glass)

Flint (or Chert)

Microcrystalline quartz (SiO2)

Silver (Native Silver Mineral)

Ag (Native Silver), Alloyed 90% Ag / 10% Cu

Blue Glass or Slag Glass

Amorphous Silica (Anthropogenic Glass)

Blue Goldstone

Synthetic Avanturine Glass (or Aventurine Glass)

Obsidian arrowhead

Volcanic glass (predominantly rhyolitic SiO₂)

Chert (variations include Flint/Jasper)

Cryptocrystalline Quartz (SiO2)

Sandstone

Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)

Chert Nodule

Microcrystalline Quartz (SiO2)

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Quartzite

Quartzite (primarily SiO2)

Nephrite Jade

Ca2(Mg, Fe)5Si8O22(OH)2

Diamond

Carbon (C)

Tumbled chalcedony (likely carnelian/agate)

Microcrystalline quartz, SiO₂; chalcedony, with possible iron-oxide coloring

Red Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Desert Varnish on Sandstone

Quartz Arenite with Iron-Manganese Oxide Coating

Aluminum Slag

Anthropogenic Aluminum (Al)

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Opalite

Synthetic Opalized Glass (SiO2 + additives)

Limonite on Sandstone

Iron Oxyhydroxide (FeO(OH)·nH2O) on Quartz Sandstone

Limonite (Ironstone Concretion)

Limonite: FeO(OH)·nH2O