Man Made Glass (Often Grouped With Minerals In Lapidary)

Polished labradorite pendant

Labradorite, a calcium-rich plagioclase feldspar (approximately NaAlSi₃O₈–CaAl₂Si₂O₈)

Colorless quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Concrete with Exposed Aggregate

Anthropogenic conglomerate (Concrete)

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Polished silver sheen obsidian heart

Obsidian (volcanic glass), primarily rhyolitic silica-rich glass

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Blue Goldstone

Synthetic glass with copper or cobalt/manganese inclusions

Asphalt Concrete (Bituminous Pavement)

Aggregates in Bitumen Matrix

Concrete / Anthropogenic Conglomerate

Man-made composite material (Portland cement, aggregate, and water)

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

Dyed Crackle Quartz (Green)

Quenching-treated Quartz (Silicon Dioxide, SiO2)

Sandstone-based Concrete Fragment

Cementitious Composite with Sedimentary Aggregate

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Concrete with Aggregate

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

Green Slag Glass

Cullet (Amorphous Silicon Dioxide with impurities)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC) / Moissanite (natural)

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by nature)

Ocean Jasper Mushroom

Orbicular Jasper (Silicon Dioxide, SiO2 mixed with various impurities)

Sea Glass

Amorphous Silicon Dioxide (Man-made glass weathered by nature)

Red Sandstone or Brick Fragment

Arenite (if sandstone)

Sandstone Concretion

Clastic Sedimentary Rock (primarily SiO2 with mineral cement)

Felsic Drill Core (likely Gneiss or Granite)

Felsic Metamorphic Rock (Gneissic profile)

Blue-dyed tumbled quartz or glass imitation

Quartz (SiO₂), appearance possibly enhanced with blue dye; identity uncertain from image

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Carved Mottled Greenish-Yellow Crystal/Glass Object

Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.

Green glassy mineral fragment, possibly fluorite

Fluorite (calcium fluoride, CaF₂), tentative identification

Goldstone (likely red/brown aventurine glass)

Man-made aventurine glass; copper-bearing silicate glass (not a natural mineral)

Cubic Zirconia (Jewelry Setting)

Zirconium Dioxide (ZrO2)

Blue Goldstone

Aventurine Glass (SiO2 with Cobalt/Copper inclusions)

Cubic Zirconia (Jewelry Setting)

Cubic Zirconia (ZrO2)

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Green Quartzite

Metamorphic Quartzite (often colored by chromium-bearing minerals or fuchsite)

Dyed Aura Quartz

Silicon Dioxide (SiO2) with metallic coating

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Polished black pebble, possibly obsidian

Volcanic glass (obsidian), likely; identification is tentative from the image

Man-made Crystal (Lead Glass)

Lead oxide-doped Silica Glass (approx. SiO2 + PbO)

Banded brown jasper (likely picture jasper)

Silicified microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained

Polished brown jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions