Organic Material (Likely A Fruit Or Berry)

Weathered limestone or calcareous sandstone

Likely micritic limestone (calcite, CaCO₃), possibly carbonate-rich sandstone

Orange cabochon gemstone, likely amber or amber-like resin

Natural amber: fossilized plant resin (organic mineraloid), commonly succinite; exact identification requires testing

Quartz-bearing metamorphic rock, likely garnet-mica schist

Quartz–mica schist with probable garnet and iron-oxide minerals

Tumbled brown chalcedony or jasper

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Petrified Wood

Silicified wood (Quartz / Chalcedonized wood, SiO2)

Mixed collection of common river stones

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

Quartz-rich rock, possibly milky quartz or quartzite

Quartz (silicon dioxide, SiO₂); if granular and foliated, likely quartzite

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

Quartz (likely Rose Quartz or Milky Quartz based on color)

Quartz (SiO2 - Silicon Dioxide)

Tumbled orange chalcedony and a gray stone disk

Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate

Micaceous Sandstone or Quartzite

Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)

Blue Quartzite (Dyed)

Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)

Grey River Pebble (Likely Quartz-rich or Limestone)

Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)

White quartz geode

Quartz, silicon dioxide (SiO₂), likely a druzy quartz geode

Likely polished black stone or obsidian

Obsidian (volcanic glass), chiefly SiO₂

Gemstone Ring

Various (Likely Glass, Cubic Zirconia, or assorted semi-precious stones)

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil cockle or clam shell, aragonite/calcite replaced or preserved

Tumbled amethyst with possible lepidolite/colored quartz companion

Amethyst, purple quartz (SiO₂), likely with iron-related color centers

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)

Fluorite (likely)

Calcium Fluoride (CaF2)

Jasper and Quartz River Pebble

Silicon Dioxide (SiO2) with impurities

Small polished pink-and-white mineral pebble

Likely rose quartz or pale pink quartz; exact identification is uncertain from the image

Iron-stained milky quartz

Quartz (SiO₂), mainly massive or vein quartz, with reddish-brown iron-oxide staining and possible minor feldspar or other vein minerals

Petrified Wood

Silicified Wood / Fossilized Wood (SiO2)

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Polished agate/jasper pebble

Microcrystalline quartz (chalcedony), SiO₂, with likely iron-oxide and clay inclusions

Polished malachite slab

Malachite, Cu₂CO₃(OH)₂; likely polished and possibly resin-stabilized

Fossilized Wood (Petrified Wood)

Silicified Wood (primarily quartz/chalcedony replacing organic matter)

Rounded pale quartz-rich pebble

Likely milky quartz or quartzite (SiO₂); exact identification is uncertain from the photograph

Banded Chert

Cryptocrystalline Quartz (SiO2)

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂), likely massive or coarsely crystalline; brown areas are limonite/goethite staining

Banded Iron Formation (BIF) with Quartz

Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)

Fossilized bivalve shell in limestone

Calcitic fossil shell; likely an oyster or other rudist/bivalve (Bivalvia), preserved in carbonate rock

Tumbled black-and-white banded stone, likely onyx or agate

Cryptocrystalline quartz (SiO₂), probably banded chalcedony/onyx

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Blue magnesite beads

Magnesite (MgCO₃), likely stabilized or dyed; brown veining may reflect matrix or iron oxides

Garnet-bearing granite or pegmatitic granitic rock

Coarse-grained granitoid, likely granite or pegmatite, composed mainly of quartz and feldspar with almandine/spessartine garnet and dark biotite or amphibole

Mixed tumbled gemstone collection

Varied minerals, likely including amethyst, sodalite/lapis lazuli, quartzite or aventurine, jasper, and agate/chalcedony

Milky quartz with iron staining

Quartz, silicon dioxide (SiO₂)

Pyrite

Pyrite (FeS2)

Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)

Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.

Copper ore with native copper and quartz/calcite

Malachite–chrysocolla–cuprite-bearing copper ore, likely with quartz or calcite gangue