Sedimentary Rock Or Mineral (Depending On Origin And Purity)

Blue-gray mineral specimen (possibly sodalite)

Undetermined; appearance may be consistent with sodalite (Na₈Al₆Si₆O₂₄Cl₂), but the image is insufficient for reliable identification

Green-and-white quartz-rich rock, likely chrysoprase or serpentine-bearing stone

Uncertain; possible chrysoprase (microcrystalline quartz, SiO₂) or serpentinite (magnesium silicate minerals)

Tektite

Natural impact glass

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

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Turquoise Beads

CuAl6(PO4)4(OH)8·4H2O

Native Silver Nugget

Silver (Ag)

Sandstone (Ferruginous)

Arenite (with Iron Oxides)

Blue Sapphire

Corundum (Al2O3 with iron and titanium trace elements)

Faceted Gemstone

Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass

Mixed rounded river gravel

Polymictic alluvial gravel; likely mixtures of quartzite, granite, basalt, sandstone, and other silicate rocks

Greenstone (likely chlorite-rich greenschist)

Greenschist facies metamorphic rock, typically composed of chlorite, actinolite, and albite; exact identification requires testing

Breccia

Clastic Breccia (General mineral composition depends on fragments, often SiO2 or CaCO3)

Sandstone / Weathered Quartzite

Sandstone (Quartz Arenite)

River Rock / Stream Pebble

Fluvial Clast / Rounded Sedimentary Particle

River Rock

Mixed lithology clast

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Granite (Polished Countertop Surface)

Plutonic Igneous Rock (Felsic)

Flint

Microcrystalline quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Druzy Quartz (on Geode Fragment)

Silicon Dioxide (SiO2)

Spider Conch Shell

Lambis lambis (Calcium Carbonate, CaCO3)

Mixed Mineral and Fossil Collection

Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)

Sandstone

Arenite (SiO2 + various cementing minerals)

Sandstone

Arenite

Gold Nugget / Native Gold

Native Gold (Au)

Weathered brown rock, possibly iron-rich sandstone or limonite

Tentative: ferruginous sandstone (quartz with iron oxides) or limonite/goethite-rich material

Ruby

Corundum (Al2O3 with Chromium traces)

Emerald In Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Sandstone

Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)

Educational Geologic Collection

Mixed Mineral and Rock Collection (Various compositions)

Possible basaltic volcanic rock or iron-rich meteorite

Likely basalt (plagioclase–pyroxene rock); meteorite status cannot be confirmed visually

Dark brown mineral fragments, possibly garnet or iron-rich rock

Indeterminate from image; possible almandine garnet (Fe₃Al₂Si₃O₁₂) or limonite-rich material

Painted beach pebble

Unidentified natural pebble; underlying lithology cannot be determined from the image

Specular hematite (likely iron-rich ore)

Hematite, Fe₂O₃; possibly magnetite-bearing

Milky Quartz (Crystal Cluster)

Silicon Dioxide (SiO2) - Quartz Variety

Opal ring

Precious opal, hydrated amorphous silica (SiO₂·nH₂O), set in a metal ring

Emerald crystal in host rock

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Sandstone with Concretions / Liesegang Rings

Arenite with iron oxide banding

Turquoise

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O