Mineral (Processed Alloy)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Blue Apatite

Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)

Nephrite Jade

Nephrite

Sandstone

Arenite (primarily SiO2)

Fossil Shark Tooth

Chondrichthyes (tooth)

Fossil Shark Tooth

Chondrichthyes teeth

Green stone fragment (unidentified)

Undetermined; possibly serpentine or greenstone, but the image is insufficient for identification

Mixed polished stone and mineral collection

Several small, tumbled specimens; individual species cannot be identified reliably from the image

Sandstone Pebble

Arenite (predominantly SiO2)

Small amber-colored mineral fragment (identity uncertain)

Undetermined; appearance alone is insufficient for a reliable mineral identification

Rock specimen shown in a classroom identification activity

Undetermined; the pictured specimen may be a fine-grained, pinkish rock, but the image does not provide enough detail for a reliable identification

Small tan stone (undetermined)

Unidentified fine-grained geological material; species cannot be determined from the image

Milky Quartz

Silicon Dioxide (SiO2)

Unidentified pink-and-gray mineral or rock specimen

Undetermined; the image is too blurry for reliable identification

Native gold (gold nugget)

Native gold, Au; commonly alloyed with silver and copper (electrum when silver-rich)

Green Calcite

Calcite (Calcium Carbonate, CaCO3)

Serpentinite (likely)

Serpentinite, composed mainly of serpentine-group minerals such as antigorite, lizardite, or chrysotile

Arsenopyrite with Schist Matrix

Arsenopyrite (FeAsS)

Fossilized Shark Tooth

Chondrichthyes tooth

Small dark stone (unidentified)

Undetermined; image lacks enough detail for reliable identification

Shark Tooth Fossil

Chondrichthyes tooth

Small pale mineral fragment, possibly calcite

Unidentified; calcite (CaCO₃) is one possibility

Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)

Mixed Silicates and Sulfides (SiO2, FeS2)

Carved Stone Turtle

Carved Soapstone and Quartz

Calcite–fluorite mineral specimen with iron-oxide staining

Calcite (CaCO₃), likely fluorite (CaF₂), with possible quartz and iron/manganese oxides

Yellow Calcite

Calcium Carbonate (CaCO3)

Small rough mineral or rock fragment (not identifiable from the image)

Undetermined; the specimen is too small and lacks diagnostic visible features for a reliable identification

Orange Calcite

Calcium Carbonate (CaCO3)

Shark Tooth Fossil

Carcharocles megalodon or similar extinct shark tooth

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Biotite (Mica)

Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)

Limonite Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Lujavrite

Nepheline Syenite

Jasper and Chalcedony Composite

Silicon Dioxide (SiO2) microcrystalline quartz

Small brown mineral or rock fragment

Undetermined; the image does not show enough diagnostic detail for reliable identification

Fossilized Bone

Permineralized Vertebrate Fossil

Fossilized Shark Tooth

Chondrichthyes tooth fossil

Shark Tooth Fossil

Chondrichthyes fossil

Tiger's Eye

Silicon Dioxide (Quartz pseudomorph after crocidolite)

Possible dark garnet or other rough mineral fragment

Undetermined; the image does not show enough diagnostic detail to identify a species

Small tan mineral or rock fragment (undetermined)

Unidentified; the image does not provide enough detail for a reliable identification