Sedimentary (Processed Mineral Product)

Yellow calcite cabochon

Calcite (calcium carbonate, CaCO₃), likely honey/yellow calcite

Hematite

Iron(III) oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Small weathered rock fragment

Indeterminate; possibly limestone or altered volcanic rock

Sandstone (with Lichen)

Arenite (primarily SiO2)

Possible ironstone concretion or weathered sulfide-bearing rock

Indeterminate from the photograph; possibly goethite/limonite-rich ironstone

Possible ironstone concretion

Iron-oxide-rich concretion, likely hematite/goethite; exact identification is uncertain from the photo

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Kyanite

Kyanite (Al2SiO5)

Opalite

Man-made glass (traditionally simulated Opal)

Likely iron-rich slag or weathered ironstone fragment

Uncertain; possibly iron oxide–rich material (hematite/goethite) or industrial iron slag

Weathered granite pebble

Granite, mainly quartz, feldspar, and mica; approximate composition SiO₂-rich continental crust

Tumbled banded agate beads

Agate, microcrystalline quartz (SiO₂), a variety of chalcedony

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Road-surface aggregate (crushed stone)

Unidentifiable mixed lithic aggregate; likely basaltic/andesitic fragments with feldspar, quartz, and weathered rock

Polished druzy quartz specimen

Quartz (SiO₂), likely druzy quartz with possible blue chalcedony or inclusions

Likely pyrite-bearing rock or pyrite fragment

Pyrite (FeS₂), possibly mixed with quartz or carbonate matrix

Quartz pebble in concrete

Quartz (SiO₂), embedded in Portland-cement concrete

Hematite

Iron(III) oxide (Fe2O3)

Fluorite (Rainbow Fluorite)

Calcium Fluoride (CaF2)

Tumbled Hematite

Iron(III) oxide (Fe2O3)

Biotite-rich mica schist

Mica schist, likely containing biotite and quartz with possible feldspar

Black Obsidian

Extrusive Volcanic Glass (primarily SiO2)

Yellow Ochre / Limonite

FeO(OH)·nH2O (Hydrated Iron Oxide Mix)

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminum silicate), likely with malachite/azurite and copper sulfides

Raw honey calcite (likely)

Calcite, CaCO₃

Kyanite

Al2SiO5

Opalite (likely man-made glass)

Opalite; amorphous silica glass, not a natural mineral

Hematite bead bracelet

Hematite (Fe₂O₃), likely polished or magnetically enhanced beads

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Epidote

Ca2(Al,Fe)3(SiO4)3(OH)

Blue Goldstone

Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)

Heart-shaped polished howlite (likely dyed or stabilized)

Howlite, Ca₂B₅SiO₉(OH)₅; possibly sold as imitation turquoise

Dyed Fuchsia Tiger’s Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Milky Quartz with Chlorite / Mica inclusions

Silicon Dioxide (SiO2) with phyllosilicate inclusions

Chert (Sedimentary Rock)

Silicon Dioxide (SiO2)

Petrified Coral (Agatized Coral)

Fossilized Anthozoa (Silicon Dioxide replacement - SiO2)

Small white mineral fragment

Likely quartz (SiO₂), possibly calcite (CaCO₃)

Hematite (Concretion)

Iron(III) oxide (Fe2O3)

Iron-stained quartz-rich rock (possibly ironstone or ochre-coated quartz)

Undetermined ferruginous rock; yellow-brown coloration likely from goethite and/or limonite (hydrated iron oxides)

Blue Impression Jasper beads

Impression jasper (microcrystalline quartz/chalcedony), chiefly SiO₂, with iron-oxide and other mineral inclusions

Colorless quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)