Man Made Material

Metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly with chalcopyrite and quartz/host rock

Sandstone

Sandstone (clastic sedimentary rock)

Quartz (Float/Abraded)

Quartz (SiO₂)

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Talc

Talc (Mg₃Si₄O₁₀(OH)₂)

Vesicular basalt (weathered volcanic rock)

Basalt, chiefly plagioclase feldspar, clinopyroxene, and possibly olivine/iron oxides

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Phyllite (possibly low-grade greenish slate)

Foliated metamorphic rock composed mainly of very fine-grained quartz, mica, and chlorite; approximate composition varies and has no single fixed chemical formula

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Likely vertebra fossil or bone fragment

Indeterminate fossilized vertebra; mineralized hydroxyapatite, commonly Ca₅(PO₄)₃(OH)

Weathered limestone or calcitic fossil/reef fragment

Calcite-rich limestone (CaCO₃), possibly fossiliferous limestone

Polished blue chalcedony or glass-like quartz specimen

Chalcedony (microcrystalline SiO₂), possibly treated or synthetic; exact identification requires testing

Unakite

Unakite (epidote-bearing altered granite; mainly pink potassium feldspar, green epidote, and quartz)

Peridot

Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)

Weathered granite cobble

Granite (quartz–feldspar–mica rock; commonly containing quartz, K-feldspar, plagioclase, and biotite)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Purple fluorite-bearing matrix specimen

Fluorite (calcium fluoride, CaF₂), likely with quartz and host-rock minerals

Tumbled honey-colored chalcedony or quartzite

Microcrystalline quartz, SiO₂; exact identification requires testing

Iron sulfide-rich ore, possibly pyrite-bearing gossan

Likely pyrite (FeS₂) with iron oxides/hydroxides and host rock; exact identification requires testing

Milky quartz vein rock

Quartz, silicon dioxide (SiO₂), likely with iron-oxide staining and minor mica or sulfide minerals

Yellow calcite crystal cluster with calcite fragment

Calcite, calcium carbonate (CaCO₃)

Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil

Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment

Granite

Granite (Felsic intrusive igneous rock)

Pearl (Biogenic Mineraloid)

Calcium carbonate (CaCO3) primarily as Aragonite

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Quartzite

Quartzite (primarily SiO2)

Quartz Geode/Cluster

Quartz (SiO2)

Polished blue agate/geode slice

Chalcedony (microcrystalline quartz, SiO₂), likely dyed blue

Likely dark rounded pebbles

Indeterminate; possibly basalt or a dark mafic mineral such as hornblende/biotite

Calcite

Calcite (CaCO3)

Tumbled amethyst

Amethyst, purple quartz (SiO₂), colored by trace iron and irradiation

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Carnelian (red chalcedony), possibly red agate or jasper

Chalcedony, a microcrystalline variety of quartz; silicon dioxide (SiO₂), commonly colored red-orange by iron oxides. The specimen may include opaque jasper or agate zones.

Tumbled green jasper (probable serpentine-rich stone)

Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite

Sandstone

Quartz Arenite (a type of sandstone composed of more than 90% quartz)

Chert (Flint)

Chert (microcrystalline quartz)

Honey calcite (calcite-rich limestone/marble fragment)

Calcite — CaCO₃; likely coarse crystalline calcitic rock

Diamond

Diamond (C)

Polished amber-colored stone, possibly chert or jasper

Uncertain from image; likely microcrystalline quartz (SiO₂) if chert/jasper

Diamond (Cut Gemstone)

Carbon (C)

Chert

Chert (Microcrystalline Quartz)

Tumbled blue-gray stone beads, likely labradorite or dyed quartz

Probable labradorite (plagioclase feldspar; approximately NaAlSi₃O₈–CaAl₂Si₂O₈), though exact identification requires testing