Synthetic Polymer (Synthetic Material)

Banded malachite cabochon

Malachite, Cu₂CO₃(OH)₂; the dark bands may be manganese-oxide or other sulfide-rich matrix, and could also indicate a composite or treated specimen

Quartz-rich pegmatitic rock (likely quartz–feldspar–mica specimen)

Granitic pegmatite; mainly quartz (SiO₂), feldspar, and dark mica/amphibole

Gray chalcedony (microcrystalline quartz)

Chalcedony, SiO₂; likely common gray/blue-gray variety

Small purple quartz crystal, likely amethyst

Amethyst: violet variety of quartz, silicon dioxide (SiO₂)

Amethyst-bearing quartz (likely polished or naturally fractured)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects

Malachite / Copper Ore

Cu2CO3(OH)2

Chrysocolla

Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O

Fossil scallop/bivalve shell

Fossilized pectinid bivalve; likely family Pectinidae (exact genus/species cannot be determined from the image)

Diamond

Carbon (C)

Greenstone

Metabasalt / Metavolcanic rock

Diamond

Carbon (C)

Slate

Metamorphic Pelitic Rock

Chert (Yellow Jasper/Flint)

Silicon Dioxide (SiO2)

Chert Pebble

Microcrystalline Quartz (SiO2)

Diamond

C (Carbon)

Slate

Foliated Metamorphic Rock

Chert / Flint Pebble

Silicon Dioxide (SiO2)

Chert / Flint

SiO2 (Silicon Dioxide)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Nephrite Jade

Nephrite

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert

Chert (SiO2)

Diamond (or Diamond Simulant/Cubic Zirconia)

Carbon (C) - if diamond, or Zirconium dioxide (ZrO2) - if Cubic Zirconia

Diabase

Diabase (also known as Dolerite)

Chert (variations include Flint or Jasper)

Aphanitic Silica (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert / Microcrystalline Quartz

Silicon Dioxide (SiO2)

Diamond (in Jewelry Setting)

Carbon (C) - Isometric-Hexoctahedral

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Aragonite Star Cluster

Aragonite (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Weathered quartz-rich rock, possibly quartzite or quartz vein material

Quartz (SiO₂), likely with feldspar, mica, and iron-oxide staining

Jasper

Microcrystalline Quartz (SiO2)

Jasper

Microcrystalline quartz (SiO2)

Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Tumbled Red Jasper

Quartz (Microcrystalline variety of chalcedony, SiO2)

Jasper

Microcrystalline quartz (SiO2)