Man Made Rock Like Material

Chert (Jasper type)

Microcrystalline Quartz (SiO2)

Granite

Phaneritic plutonic rock (SiO2 typically >69%)

Crinoid Fossil Stem Segment

Class Crinoidea (Echinodermata)

White cabochon gemstone, likely milky chalcedony or opalite

Chalcedony: microcrystalline quartz, SiO₂; appearance may also indicate synthetic opalite glass

Goldstone (blue-goldstone–style glass) beads

Artificial aventurine glass, typically silica glass with copper inclusions; not a natural mineral

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Pearl necklace

Pearl, primarily aragonite (CaCO₃) and conchiolin

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Polished blue calcite sphere (tentative identification)

Calcite, CaCO₃; blue color generally results from trace impurities or inclusions

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Basalt

Basalt (comprising Plagioclase feldspar, Pyroxene, and Olivine)

Aquamarine-like beryl pendant

Beryl, Be₃Al₂Si₆O₁₈; the beads may be dyed or treated chalcedony/amazonite, so image-only identification is uncertain

Polished greenstone/serpentine pebble (probable)

Serpentinite, dominated by serpentine-group minerals (lizardite/chrysotile); possible accessory olivine or chlorite

Tumbled ruby-in-zoisite (likely)

Ruby-bearing zoisite; zoisite Ca₂Al₃(SiO₄)₃(OH), corundum ruby Al₂O₃

Chert (often called Flint)

Chert (SiO2)

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Sandstone (Quartzose)

Sandstone (SiO2 dominated)

Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)

Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Diorite

Intermediate plutonic igneous rock

Aura Quartz (Anomalously Coated Quartz)

Silicon Dioxide (SiO2) treated with vaporized metals

Chert (Nodule)

Chert (Alpha-Quartz, SiO2)

Diamond

Carbon (C)

Green Aventurine

Quartz (SiO2) with Fuchsite inclusions

Jade bangle

Likely nephrite jade (actinolite–tremolite amphibole); possibly jadeite

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Nacre (Mother of Pearl)

Nacre (Biogenic Aragonite/Calcite composite, CaCO3)

Granite

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Diamond (in jewelry setting)

Carbon (C)

Diamond

Carbon (C)

Chert (and Jasper/Chalcedony mixture)

Microcrystalline Quartz (SiO2)

Desert Rose (Barite Rose / Gypsum Rose)

Barium Sulfate (BaSO4) or Hydrous Calcium Sulfate (CaSO4%22H2O)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Porous limestone (likely fossiliferous or weathered limestone)

Calcite-rich limestone; chiefly calcium carbonate (CaCO₃)

Likely iron-rich rock or weathered metallic mineral fragment

Uncertain; possibly limonite/goethite or iron-bearing slag

Quartzite pebble

Quartzite (SiO2)

Crackle Glass (Simulated Gemstone)

Amorphous Solid (SiO2)

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Chert (or Flint)

Chert (a cryptocrystalline variety of quartz, SiO2)