Metamorphic Or Igneous (Context Dependent)

Star Ruby

Corundum (Al2O3 with chromium and rutile inclusions)

Polished brown chalcedony (likely carnelian or sard)

Chalcedony, microcrystalline quartz (SiO₂); brown varieties are commonly termed sard, while reddish-orange material is carnelian

Tumbled cream-colored stone, possibly quartz or calcite

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Greenstone (Celadonite-bearing Volcanic)

Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Serpentinite

Serpentinite (containing minerals of the Serpentine subgroup: Antigorite, Lizardite, and Chrysotile; formula (Mg,Fe)3Si2O5(OH)4)

Sapphire

Corundum (Al2O3)

Green Aventurine

Quartz with Fuchsite inclusions (SiO2)

Aquamarine (Beryl) Beads

Beryllium aluminum silicate (Be3Al2Si6O18)

Granite

Granite (phaneritic intrusive felsic igneous rock)

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Quartz in Matrix (or Quartz Vein Rock)

Silicon Dioxide (SiO2) with host rock

Stromatolite (stromatolitic limestone)

Laminated microbial carbonate, chiefly calcite (CaCO₃); precise species or age cannot be determined from the photo

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock pebble

Yellow Aventurine (specifically a carved crescent moon)

Silicon Dioxide (SiO2) with inclusions

Obsidian (likely)

Volcanic glass, predominantly silica-rich rhyolitic composition (no fixed mineral formula)

Orange Aventurine / Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Glass

Amorphous Silicon Dioxide (SiO2)

Sapphire (Blue/Violet Rough)

Corundum (Al2O3)

Lepidodendron Plant Fossil

Lepidodendron sp. (Lycopodiophyta)

Schist (Biotite/Mica Schist)

Medium-grade regional metamorphic rock (rich in Phyllosilicates)

Granite pebble

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

Eudialyte in Matrix

Na15Ca6(Fe,Mn)3Zr3(Si,Nb)(Si25O73)(O,OH,H2O)3(Cl,OH)2

Fossilized bone fragment

Fossil bone, composed chiefly of carbonate-fluorapatite (bioapatite)

Bull Quartz with Mica and Host Rock

Massive Quartz (SiO2) with Muscovite/Chlorite inclusions

Gray volcanic rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and minor olivine/iron oxides

Quartz-rich rock, likely milky quartz vein material

Predominantly quartz (SiO₂); exact rock type cannot be confirmed from the photograph

Green Aventurine

Quartz with Fuchsite inclusions (SiO2)

Red-and-white jasper/chalcedony pebble

Microcrystalline quartz (SiO₂), likely hematite- or iron-oxide-bearing jasper with white chalcedony/quartz

Arsenopyrite in Quartz Matrix

Arsenopyrite (FeAsS) with Quartz (SiO2)

Quartz Pebble (River Agate / Chalcedony)

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Jasper / Chert (Red)

Cryptocrystalline quartz (SiO2)

Mica Sand / Vermiculite

Phyllosilicate group (typically Biotite or Muscovite)

Quartz-bearing rock fragment

Likely quartz (SiO₂) with iron-oxide staining and possible feldspar/matrix minerals

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Agatized Jasper / Chalcedony

SiO2

Quartz Vein

Silicon Dioxide (SiO2)

Vesicular basalt (scoria-like volcanic rock)

Basalt, composed mainly of plagioclase, pyroxene, and olivine; abundant vesicles formed by trapped gas

Milky Quartz

Silicon Dioxide (SiO2)