Unknown (Likely Sedimentary Or Metamorphic)

Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Pale green translucent mineral fragment

Indeterminate; possibly fluorite, calcite, or glassy quartz

Mossy Rock

Mixed lithology rock with Bryophyta (moss)

Jasper

Silicon dioxide (SiO2) with impurities

Chalcedony (Tumbled Pebble)

Silicon Dioxide (SiO2)

Unidentified gray-brown stone

Likely fine-grained quartz–feldspar rock; exact identification is not possible from this close, blurred image

Carved Mottled Greenish-Yellow Crystal/Glass Object

Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.

Mixed river stones and gravel

Polymictic alluvial clasts; individual pieces may include quartzite, granite, basalt, sandstone, limestone, and slate

Dark rounded pebble

Likely basalt or another fine-grained mafic volcanic rock; exact identification is uncertain from the image

Magnetite or Ironstone Nodule

Magnetite (Fe3O4) or Hematite-rich Sedimentary Nodule

Pink Himalayan Salt Rock (Halite)

Halite (Sodium Chloride, NaCl)

Amethyst and Calcite collection

Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)

Limonite or Goethite (Ironstone)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Weathered dark mineral/rock fragment

Indeterminate; possibly iron-rich basalt, slag, or a sulfide-bearing mineral

Mixed Mineral Collection

Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)

Serpentine-rich ultramafic rock

Serpentinite (predominantly serpentine-group minerals: lizardite, chrysotile, and/or antigorite)

Weathered schist or phyllite

Mica schist/phyllite, likely quartz–mica-rich metamorphic rock

Apatite

Fluorapatite (Ca5(PO4)3F)

Rose quartz (probable)

Quartz, SiO₂; pink coloration typically from trace inclusions or irradiation-related defects

Small weathered mineral/rock fragment

Indeterminate; possibly quartz-bearing feldspathic rock or calcite-rich specimen

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Rounded gray stone, likely slate or fine-grained sandstone

Probable slate (low-grade metamorphosed shale) or lithic sandstone; exact identification requires testing

Tiny rounded metallic-looking pebble, possibly pyrite or a metal-rich mineral

Uncertain from image; possible pyrite (FeS₂), chalcopyrite (CuFeS₂), or magnetite (Fe₃O₄)

Light-colored pebble, likely quartzite or weathered limestone

Indeterminate from image; possible quartzite (microcrystalline SiO₂)

Small red-brown mineral or rock fragment

Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide

Small white mineral fragment

Likely quartz (SiO₂), possibly calcite (CaCO₃)

Tumbled brown stone, possibly amber or polished agate

Indeterminate from image; possibilities include amber (fossilized plant resin, organic) or chalcedony/quartz (SiO₂)

Iron-stained quartz fragment (probable quartzite or chert)

Quartz, SiO₂; possibly iron-oxide-stained microcrystalline silica

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Mixed collection of common river stones

Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material

Yellow Aventurine

Silicon Dioxide with inclusions (SiO2 + Muscovite/Fuchsite)

Carnelian

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Chalcedony (Agate) Pebble

Silicon Dioxide (SiO2)

Fossilized bone fragment (probable mammalian tooth or bone)

Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite

Clear quartz crystals

Quartz (silicon dioxide, SiO₂)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Serpentine (polished/tumbled)

Serpentinite; chiefly antigorite, lizardite, and chrysotile, commonly with magnetite and carbonate minerals

Quartz-rich limestone or calcitic marble

Calcite (CaCO₃), possibly with quartz (SiO₂)

Dark gray rounded river pebble

Likely basalt or fine-grained volcanic rock; exact identification requires testing

Rounded quartz-rich cobble

Likely quartzite or quartz-rich sandstone; exact identification requires a fresh break or hardness test