Mineraloid (Human Made Geological Specimen)

Basalt (River Stone/Pebble)

Basalt (Extrusive Igneous Rock)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone (Pebble)

Arenite (primarily SiO2)

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Banded Agate (River Stone)

Agate (Silicon Dioxide - SiO2)

Rounded white pebble, likely quartz-rich rock

Most consistent with quartzite or milky-quartz pebble; exact identification requires testing

Pyrite

Iron Sulfide (FeS2)

Botryoidal chalcedony (likely druzy agate)

Microcrystalline quartz, SiO₂, with iron-oxide inclusions

Iron-stained quartz (likely quartzite or quartz-rich rock)

Quartz, silicon dioxide (SiO₂), with iron-oxide staining

Orange Calcite

Calcium Carbonate (CaCO3)

Satin Spar (often marketed as Selenite)

Fibrous Gypsum (CaSO4·2H2O)

Amber

Succinite (fossilized tree resin)

Quartz

Silicon Dioxide (SiO2)

Polished striped jasper pebble

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

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Dendritic Jasper

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Amber

Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)

Labradorite

Labradorite (Ca, Na)(Al, Si)4O8

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Agate

Silicon dioxide (Chalcedony), SiO2

Quartz (Iron-stained or Milky Quartz)

Silicon Dioxide (SiO2)

Amber

Succinite (Fossilized Tree Resin)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite Pebble (with Iron Staining)

Quartzite (SiO2)

Rhyolitic jasper / brecciated jasper

Silica-rich volcanic rock, chiefly microcrystalline quartz (SiO₂), with iron-oxide and clay/mineral impurities

Quartz geode / iron-stained quartz vein rock

Quartz (SiO₂), likely with iron oxides and minor feldspar or host-rock minerals

Granitic Pegmatite with Schorl Tourmaline

Granitic Pegmatite (Schorl: NaFe3Al6(BO3)3Si6O18(OH)4)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides

Weathered iron-rich sandstone or conglomeratic sedimentary cobble

Ferruginous sandstone, possibly polymictic conglomerate

Bog Iron (Limonite Concretion)

Limonite (FeO(OH)·nH2O)

Aura Quartz (Titanium-coated Quartz)

Silicon Dioxide (SiO2) with metallic vapor coating

Basalt (Road Aggregate)

Basalt (Aphanitic Mafic Igneous Rock)

Yellow Chalcedony

Silicon Dioxide (SiO2)

Milky quartz–rich rock

Quartz (SiO₂), likely massive milky quartz with minor dark inclusions

Amber

Succinite (formula varies, primarily C10H16O)

Brown Jasper

Jasper (a cryptocrystalline variety of Quartz, SiO2)

Weathered sandstone pebble

Clastic sandstone, predominantly quartz (SiO₂) grains cemented by silica, calcite, or iron oxides

Iron-rich breccia or weathered ironstone

Goethite–hematite-bearing limonite, possibly brecciated host rock

Yellow Quartz (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Purple fluorite (likely cubic crystal aggregate)

Fluorite, calcium fluoride (CaF₂)