Not A Rock (Man Made Industrial Metal)

Tumbled opalite (likely man-made glass)

Opalite glass; a synthetic opalescent glass, not a natural mineral species

Red cabochon gemstone ring (likely glass or synthetic stone)

Undetermined; the image does not establish a natural mineral identity

Graphitic schist (probable)

Graphite-bearing mica schist; chiefly quartz, mica, graphite, and possibly feldspar

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Green Aura Quartz (Titanium treated Kyanite or Quartz)

Silicon Dioxide (SiO2) or Aluminum Silicate (Al2SiO5) with Titanium/Metal Oxide coating

Quartzite

Metamorphic rock primarily composed of Quartz (SiO2)

Obsidian (Blue)

Volcanic Glass (SiO2)

Blue Cracked Quartz (Dyed Fire Crackle Quartz)

Silicon Dioxide (SiO2) with synthetic dye

Pink Quartz / Sea Glass

Silicon Dioxide (SiO2)

Iron-stained quartz-rich rock (probable quartzite or silicified breccia)

Quartz-dominant aggregate, chiefly SiO₂, with iron oxides/hydroxides

Native silver fragment (probable)

Silver, Ag; possibly silver-bearing sulfide or plated metal

Cut diamond tennis-chain jewelry

Diamond, crystalline carbon (C), cubic crystal system

Quartz-veined Metamorphic Rock

Quartz Vein in Phyllite or Schist (SiO2 in Silicate Matrix)

Mounted faceted gemstone ring

Likely diamond (carbon, C), though the image is insufficient for definitive identification

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

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

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

Honey Calcite (Yellow Calcite)

Calcium Carbonate (CaCO3)

US Penny

Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy

Slag (Industrial Glassy Byproduct)

Ferro-silicate Slag

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

Possible weathered metal-rich rock or slag fragment

Uncertain; possibly iron-oxide-rich breccia or industrial slag

Blue opalite glass (likely man-made)

Opalite glass; a silica-based amorphous glass, not natural opal

Dolerite (Diabase)

Dolerite / Diabase

Cherry Quartz with Rose Quartz

Crystalline Quartz (SiO2) with glass-based synthetic components

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Faceted clear gemstone, likely quartz or glass imitation

Most likely quartz (SiO₂); exact identification requires refractive-index and hardness tests

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Luminous Stone (Glow-in-the-dark Synthetic/Man-made Stone)

Strontium Aluminate tinted glass or resin (Crystalline silicate/oxide mix)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Clear faceted gemstone in a gold-colored setting

Likely colorless quartz (rock crystal) or synthetic cubic zirconia; visual identification is inconclusive

Opalite

Synthetic Opalized Glass

Pyrite

Iron Sulfide (FeS2)

Quartz-rich hydrothermal ore rock, likely gold-bearing quartz vein

Milky quartz (SiO₂) with iron-oxide staining and probable sulfide minerals; host rock may be schist or altered granite

Serpentine

Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4

Quartz Vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Pelitic or Shaly Matrix

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Goldstone (Red)

Aventurine Glass (Cupriferous glass)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Aura Quartz

Silicon Dioxide (SiO2) with metallic vapor coating