Man Made Object (Coin)

Polished banded agate pendant

Agate, a microcrystalline variety of chalcedony (SiO₂)

Polished jasper pendant

Jasper, microcrystalline quartz (SiO₂) with iron-oxide and other mineral inclusions

Clear Quartz (Faceted)

Silicon Dioxide (SiO2)

Chert (likely jasper/chalcedony-rich chert)

Microcrystalline quartz, SiO₂

Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin

Polished agate bead bracelet

Agate, a banded microcrystalline variety of quartz (SiO₂), likely mixed-color dyed or naturally colored chalcedony

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant

Colorless faceted quartz-like gemstone

Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia

Silver Nugget

Native Silver (Ag)

Polished red jasper beads

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

Unidentified brown stone

Indeterminate from the image; possibly a common iron-stained mineral or rock fragment

Likely rough pink feldspar or rose quartz

Most likely microcline feldspar (KAlSi₃O₈) or rose quartz (SiO₂)

Blue chalcedony bead necklace

Chalcedony, microcrystalline quartz (SiO₂), commonly blue-dyed or blue-gray natural chalcedony

Serpentinite (Polished Egg)

Serpentinite (composed mainly of serpentine group minerals, Mg3Si2O5(OH)4)

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

Likely polished dark gemstone cabochon

Indeterminate; possibly black chalcedony/agate, obsidian, or glass imitation

Polished/tumbled pale-yellow stone, possibly calcite

Likely calcite (CaCO₃); identification is uncertain from the image alone

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil clam or cockle

Red Jasper Cube

SiO2 (microcrystalline quartz)

Worn River Pebble with Fossil Indentation

Sedimentary Rock with Fossil Infill

Polished black obsidian

Volcanic glass; primarily rhyolitic SiO₂, with minor iron, magnesium, and other trace elements

River Pebble (likely Quartzite or Chert)

Sedimentary Clast (Silicon Dioxide dominant)

Botryoidal chalcedony with quartz vug

Microcrystalline quartz, SiO₂ (chalcedony), with a drusy quartz-lined cavity

Tumbled purple chalcedony or low-grade amethyst bead bracelet

Chalcedony (microcrystalline SiO₂), possibly quartz/amethyst; composition is SiO₂

Fossilized shell or coral fragment

Indeterminate biogenic carbonate; likely calcite/aragonite (CaCO₃)

Tanzanite

Blue/Violet Variety of Zoisite (Ca2Al3(SiO4)3(OH))

Unable to identify - Image contains non-geological items

Likely iron-rich concretion or weathered rock pebble

Uncertain from the image; possibly an iron-oxide-cemented concretion (goethite/hematite)

Ammonite fossil

Ammonoidea; likely a Jurassic or Cretaceous ammonite

Blue slag glass or dyed glass-like industrial material

Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass

Red-and-brown agate bead bracelet

Agate, a microcrystalline variety of quartz (SiO₂), likely colored chalcedony/carnelian

Goldstone (blue-goldstone–style glass) beads

Artificial aventurine glass, typically silica glass with copper inclusions; not a natural mineral

Painted River Rock (likely Quartzite or Granite)

Quartzite or Granitic Gneiss (painted)

Siltstone or Limestone Beach Pebble

Siltstone / Micritic Limestone

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Blue calcite sphere

Calcite (CaCO₃), commonly blue-calcite variety

Small brown pebble or possible shell fragment

Unidentified natural clast; the image is too small and blurred for reliable identification

Stone bead bracelet

Unidentified polished natural-stone beads; possibly wood-grain jasper, agate, or serpentine

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

Painted pebble, likely a smooth river stone

Unidentified fine-grained natural rock; exact lithology cannot be determined from the image

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

Likely yellow calcite

Calcite (CaCO₃)