Not A Rock (Man Made Origin)

Hematite Beads

Hematite (Fe2O3)

Fluorite on Matrix

Calcium Fluoride (CaF2)

Milky quartz with dark mineral inclusions

Quartz, SiO₂; dark inclusions are not identifiable from the image

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Shungite (or Black Onyx / Obsidian)

Amorphous Carbon (Shungite) / SiO2 (Onyx/Obsidian)

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Blue goldstone

Man-made aventurine glass containing metallic copper particles; not a natural mineral

Likely polished quartz or glass-like mineral cabochon

Probably quartz (SiO₂), though the image cannot exclude man-made glass

Iron-rich meteorite candidate

Unclassified stony-iron or iron meteorite; possible weathered ordinary chondrite

Dalmatian jasper beads

Commercially “Dalmatian jasper”; commonly spotted, silica-rich rock sold as jasper, though many specimens are feldspar-rich rock rather than true jasper (microcrystalline quartz).

Banded dark pebble (likely gneiss or banded metamorphic rock)

Indeterminate from the image; possibly banded gneiss

Dark gray-blue stone fragment

Unidentified fine-grained rock; the image is insufficient for a reliable species-level identification

Rounded river cobble, likely weathered sandstone or quartzite

Indeterminate clastic silicate rock; possibly quartz-rich sandstone (SiO₂-dominant)

Piddock-bored Mudstone

Lutite (Siltstone or Mudstone) with Pholad borings

Red garnet stud earrings (likely garnet)

Garnet group; most likely almandine, Fe₃Al₂(SiO₄)₃. The image alone cannot confirm the stone or whether it is natural.

Manganese Dendrite on Siltstone

Manganese Oxide (pyrolusite or psilomelane) Dendrites

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Granite

Felsic intrusive igneous rock

Granite

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

Blue glassy mineral specimen, possibly dyed or synthetic

Uncertain; possible blue fluorite (CaF₂), dyed chalcedony, or man-made glass

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Granite

Intrusive igneous rock

Likely serpentinite (green serpentine rock)

Serpentinite, composed chiefly of serpentine-group minerals (antigorite, lizardite, and/or chrysotile)

Sandstone

Arenite

Moldavite

Tektite (Natural Silicate Glass)

Unidentified rough mineral/rock fragment

Indeterminate from image; possibly quartz-rich material or weathered carbonate rock

Basalt

Basalt

Granite

Phaneritic intrusive igneous rock

Gabbro

Gabbro

Polished opal

Opal, hydrated amorphous silica (SiO₂·nH₂O)

Green Glass Slag

Amorphous Silicon Dioxide (SiO2) with metal oxide impurities

Tumbled jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), commonly colored by iron oxides and hydroxides

Slate

Metamorphic Pelitic Rock

Fine-grained brown-gray rock, possibly andesite

Likely andesite or another fine-grained volcanic rock; exact identification is uncertain from the photo

Mixed collection of rocks and minerals

Assorted specimens; visible pieces may include quartz, feldspar, jasper, and other common minerals, but individual identification is uncertain from the image

Black beaded bracelet, likely black onyx or glass

Possibly chalcedony (microcrystalline quartz, SiO₂); the beads may instead be man-made glass

Quartz Crystal Cluster on Matrix

Silicon Dioxide (SiO2)

Faceted clear gemstone, likely glass or cubic zirconia

Undetermined; could be synthetic cubic zirconia (ZrO₂) or cut glass (silica-based)

Unidentified weathered rock fragment

Indeterminate; possibly vesicular basalt or weathered volcanic rock

Red jasper in gray host rock (likely hematite-stained quartzite or rhyolite)

Jasper: microcrystalline quartz (SiO₂), with iron-oxide coloration; exact host uncertain from image

Likely basalt or another dark, coarse-grained igneous rock

Possibly olivine-bearing basalt (plagioclase, pyroxene, and possibly olivine); identification is uncertain from the photo

Red jasper

Jasper, a microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides