All rocks & minerals

Turquoise (small irregular fragment)

Turquoise, hydrated copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Amber beads

Amber — fossilized tree resin; organic mineraloid, not a mineral

Polished dark pebble, possibly jasper or iron-rich quartzite

Uncertain from the photo; likely iron-stained quartz-rich rock (quartzite) or opaque microcrystalline quartz (jasper)

Likely amber (fossil resin), with pieces of pale raw amber

Amber; fossilized plant resin, an amorphous organic material rather than a mineral species

Likely banded tourmaline

Tourmaline-group mineral, probably elbaite; composition varies, approximately Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Small rounded quartz-rich pebble, possibly quartzite

Quartzite (tentative); chiefly quartz, SiO₂

Likely quartz-rich pebble

Unidentified quartz-rich rock; exact identification is not possible from the photo

Polished malachite pendant

Malachite, Cu₂CO₃(OH)₂; monoclinic copper carbonate hydroxide

Diorite

Diorite, a coarse-grained intrusive igneous rock composed chiefly of plagioclase feldspar and hornblende, often with biotite or pyroxene

Granite

Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica

Fossil oyster shell

Fossilized oyster (Bivalvia; exact genus and age cannot be determined from the image)

Polished mahogany obsidian

Obsidian, natural volcanic glass; predominantly silica-rich rhyolitic glass (SiO₂)

Fossilized tooth fragment, possibly shark tooth

Fossilized vertebrate dental material, composed chiefly of hydroxyapatite

Polished copper nugget

Native copper (Cu)

Polished brown jasper (likely iron-rich jasper)

Jasper, an opaque microcrystalline variety of quartz (SiO₂)

Banded gneiss pebble

Quartz–feldspar gneiss, possibly with biotite or amphibole

Rounded beige river pebble, likely quartz-rich sandstone

Quartz-rich sandstone (tentative; exact identification requires testing)

Dark river-worn stone, likely basalt

Fine-grained basalt (tentative; exact identification requires examination)

Polished hematite

Hematite, iron(III) oxide (α-Fe₂O₃)

Reddish vesicular volcanic rock, likely scoria

Scoria, a vesicular basaltic-to-andesitic volcanic rock

Rounded sandstone cobble

Quartz-rich sandstone (likely quartz arenite; exact composition cannot be confirmed from the image)

Light-colored rounded pebble (possibly quartzite)

Unidentified siliceous rock; quartzite is a plausible but unconfirmed identification

Milky quartz with a dark mineral inclusion

Quartz (SiO₂), likely containing a small inclusion of biotite or another dark mineral

Clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Rock crystal (clear quartz)

Quartz, silicon dioxide (SiO₂)

Dark green-gray river-worn rock, likely serpentinite

Serpentinite (rock composed chiefly of serpentine-group minerals; identification is provisional from the photograph)

Rounded red-brown ironstone cobble

Ferruginous sandstone or ironstone; commonly quartz grains cemented by iron oxides such as hematite and goethite

Polished unakite

Unakite: epidote, pink potassium feldspar (orthoclase), and quartz

Unakite

Unakite: epidote, pink potassium feldspar (orthoclase), and quartz

Milky quartz pebble

Quartz (SiO₂), massive variety

Quartz-rich pegmatite with black tourmaline

Granitic pegmatite composed chiefly of quartz, with black tourmaline (schorl); possibly feldspar

Polished unakite pebble (likely)

Unakite: epidote, pink potassium feldspar, and quartz; composition varies

Likely quartzite

Quartz-rich quartzite (predominantly SiO₂)

Tumbled orange aventurine (likely)

Quartz, SiO₂, colored by iron-bearing inclusions; exact identification is uncertain from the photo

Possible iron-stained chert (flint)

Microcrystalline quartz (SiO₂), likely colored by iron oxides

Black tourmaline (schorl)

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Quartz-bearing rock fragment

Likely quartz-rich rock with iron-oxide staining; exact identification is uncertain from the photo

Possible ironstone concretion or weathered sulfide-bearing rock

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

Pyrite (iron pyrite)

Pyrite, FeS₂; cubic iron sulfide

Pyrite (fool’s gold)

Pyrite, FeS₂

Polished purple gemstone bead, possibly amethyst

Likely amethyst, purple quartz (SiO₂); identification is uncertain from the image

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)