Industrial Byproduct (Anthropogenic Material)

Fluorescent glassy mineral specimen, possibly hyalite opal

Hyalite (hydrated amorphous silica, SiO₂·nH₂O), tentative

Tumbled amazonite

Amazonite, green microcline feldspar (KAlSi₃O₈)

Dendritic jasper/chalcedony

Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites

Laterite (Iron-rich bauxite or Gossan)

Ferricrete (Fe2O3·nH2O)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite pebble

Quartzite (SiO2)

Quartzite Pebbles

Quartzite (SiO2)

Star sapphire ring

Corundum (Al₂O₃), likely asteriated sapphire

Vesicular basalt (scoriaceous basalt)

Basalt, chiefly plagioclase feldspar and pyroxene with minor olivine; vesicles formed by trapped volcanic gas

Tiger’s-eye fragment

Chatoyant quartz, SiO₂, with pseudomorphic iron-oxide fibers

Likely sandstone or weathered quartz-rich rock fragment

Quartz-rich sandstone; exact identification is uncertain from the photograph

Amethyst (likely synthetic or treated)

Purple quartz, SiO₂; color caused mainly by trace iron and irradiation

Polished banded stone, likely zebra jasper

Zebra jasper (banded microcrystalline quartz, chiefly SiO₂, with iron-oxide and carbonate impurities)

Fossil bivalve shell

Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized

Likely weathered metallic mineral or slag fragment

Indeterminate; possibly iron-rich sulfide/oxide material or industrial slag

Diamond

Carbon (C)

Diamond

C

Likely iron-rich concretion or weathered rock pebble

Uncertain from the image; possibly an iron-oxide-cemented concretion (goethite/hematite)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Rough Diamond

Diamond (C)

Dark gray rock fragment

Indeterminate from image; possibly weathered basalt or fine-grained metamorphic rock

Diamond (in Matrix)

Carbon (C)

Polymer Clay (Mock Mineral)

Polyvinyl chloride (PVC) with plasticizers and pigment

Diamond and Sapphire

Carbon (Diamond, C) and Aluminum Oxide (Sapphire, Al2O3)

Gemstone ring with dark blue cabochons

Likely blue sapphire (corundum, Al₂O₃); the stones cannot be identified confidently from the image

Likely polished or naturally smoothed pebble with a pale mineral patch

Undetermined; possibly a dark volcanic rock with a quartz or feldspar inclusion

Anthracite coal (likely)

Anthracite; carbon-rich coal composed mainly of maceral vitrinite, with variable mineral impurities

Mixed beach-stone and tumbled-glass collection

Predominantly uncertain rocks (likely basalt, granite, and quartz-bearing stones) with anthropogenic glass; one possible banded agate or jasper

Tumbled quartz-rich pebble

Likely milky quartz with a dark mafic inclusion or attached basalt; exact identification requires testing

Red gemstone ring, possibly synthetic ruby or red glass

Unidentified red stone; ruby is corundum (Al₂O₃), but the image cannot confirm its identity

Opalite

Man-made glass (traditionally simulated Opal)

Cubic Zirconia

Cubic Zirconium Dioxide (ZrO2)

Chert (Iron-stained)

Chert (SiO2)

Diamond

Carbon (C)

Crushed Stone (Gravel/Aggregates)

Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)

Quartz-bearing pegmatitic rock, likely quartz–feldspar–mica specimen

Granitic pegmatite; primarily quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Clear Quartz / Diamond (untested)

Silicon Dioxide (SiO2) or Carbon (C)

Diamond

Carbon (C)

Quartzite

Quartzite (chiefly SiO2)

Basalt

Mafic Igneous Pebble

Likely silicon carbide (carborundum)

Synthetic silicon carbide (SiC), likely blue-green crystalline grit

Gravel and Sediment Sample

Mixed clastic sediment