Multiple

Chert / Jasper

Sedimentary Cryptocrystalline Quartz (SiO2)

Unakite

Epidotized Granite

Yellow Quartzite (Onyx Pebble)

Silicon Dioxide (SiO2) - Quartzite

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Red jasper (likely iron-rich chalcedony/jasper)

Jasper, microcrystalline quartz (SiO₂), colored mainly by hematite/goethite

Raw greenish-blue quartz-bearing mineral specimen

Likely fluorite or chalcedony/quartz; exact identification requires hardness and crystal tests

Likely galena-bearing ore or metallic sulfide rock

Possibly galena (PbS) with associated sulfide minerals; exact identification cannot be confirmed visually

Hag Stone (Holey Rock / Fossiliferous Limestone)

Limestone (CaCO3) with natural erosion / fossil cavities

Herkimer Diamond in Matrix

Quartz (SiO2) in Dolostone (CaMg(CO3)2)

Cantera Opal (Mexican Fire Opal in Rhyolite Matrix)

Hydrated amorphous silica in rhyolite (SiO2·nH2O in volcanic matrix)

Mixed gravelly conglomeratic road aggregate

Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments

Hematite

Hematite (Fe2O3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Quartzite River Cobble

Quartzite (SiO2)

Greywacke with Quartz Veins

Lithic Sandstone (Greywacke) with SiO2 inclusions

Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Mixed polished gemstone and mineral collection

Primarily quartz varieties (SiO₂), plus probable aventurine, rose quartz, amethyst, agate, jasper, serpentine, feldspar, and possibly dyed or man-made glass pieces

Crinoid Stem Fossil (Indian Bead)

Crinoid ossicle (Echinodermata)

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxidized

Lapis Lazuli (Lazurite crystals on Marble)

Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]

Rhodonite, Gray Moonstone, and White Feldspar Mix

Multiple: MnSiO3 (Rhodonite), (K,Na)AlSi3O8 (Feldspar/Moonstone)

Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)

Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)

Quartz Pebble

Silicon Dioxide (SiO2)

Yellow Quartzite River Cobble

Meta-quartzite (SiO2 with iron oxide staining)

Agate Geode Node

Cryptocrystalline Quartz (SiO2)

Banded chert or siliceous sedimentary rock

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide staining and possible carbonate/clay layers

Conglomeratic basalt (rounded volcanic breccia/pebble)

Basaltic conglomerate or polymict volcanic breccia; predominantly plagioclase–pyroxene basalt with lighter felsic or weathered clasts

Arid Sandy Loam

Arenosols / Regosols

Botryoidal Chalcedony

Cryptocrystalline Silicon Dioxide (SiO2)

Mixed river pebbles and quartz-rich specimens

Polymictic fluvial gravel; likely quartz, quartzite, chert, and weathered feldspathic rocks

Mixed rounded river pebbles, probably quartz-rich metamorphic and volcanic rocks

Predominantly quartzite/metachert, with possible rhyolite, sandstone, and iron-stained quartz; exact species cannot be determined confidently from the image

Carved Mottled Greenish-Yellow Crystal/Glass Object

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

Crushed Stone / Gravel (Multiple Rock Types)

Lithic fragments (undifferentiated)

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Fluorite

Fluorite (Calcium Fluoride - CaF2)

Mixed rock and mineral specimen collection

Multiple species, likely quartz (SiO₂), calcite (CaCO₃), feldspar, chert, and assorted volcanic/sedimentary rocks

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Zircon

Zircon (ZrSiO4)