Undetermined

Unknown Rock Fragment

Undetermined

Unidentifiable Specimen

Undetermined

Uncertain small stone; possibly weathered quartz-bearing rock

Indeterminate from image; candidate materials include quartz-rich pebble or altered silicate rock

White tumbled stone, likely quartz or calcite

Indeterminate; possibly quartz (SiO₂) or calcite (CaCO₃)

Generic Rock / Pebble

Undetermined rock specimen

Unidentified dark pebble

Undetermined; possibly polished basalt, chert, or iron-rich stone

Tiny amber-colored crystal or mineral fragment

Indeterminate from image; possibly quartz, citrine, topaz, or iron-stained feldspar

Unidentified metallic mineral fragment

Indeterminate; possibly galena, hematite, or a metallic meteorite fragment

Small metallic mineral fragment

Indeterminate; possibly galena, hematite, magnetite, or metallic meteorite fragment

Unidentified metallic-looking mineral fragment

Indeterminate; possible galena, magnetite, or metal-rich sulfide/ore fragment

Unidentified dark rock fragment

Likely fine-grained mafic mineral aggregate; exact identification requires testing

Likely weathered iron-rich rock fragment

Indeterminate; possibly limonite/goethite-bearing sandstone or ironstone

Likely polished black-and-white stone fragment

Indeterminate from image; possibly tourmalinated quartz, black-and-white jasper, or coated stone

Iron-rich reddish rock, possibly weathered basalt or ironstone

Indeterminate; likely oxidized mafic rock containing iron oxides and silicate minerals

Uncertain dark-and-white rock fragment

Likely a mixed lithic specimen, possibly quartz-bearing granite or ore; exact identification is not possible from the photograph

Unknown dark mineral fragment

Indeterminate; possibly a dark silicate mineral or slag-like geological fragment

Weathered brown rock fragment

Indeterminate; possibly weathered granite, gneiss, or iron-stained quartz-rich rock

Rounded greenish pebble

Indeterminate; likely weathered quartzite, greenstone, or altered volcanic rock

Unidentified brown rock fragment

Indeterminate from image; likely a weathered iron-rich lithic fragment

Uncertain fine-grained rock or mineral-bearing specimen

Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains

Blue-gray mineral/rock fragment

Indeterminate; possibly azurite-bearing material, blue chalcedony, or dyed/coated stone

Dark mineral-rich rock fragment

Indeterminate; possibly dark quartzite, chert, or weathered igneous rock

Unidentified small tan stone

Likely quartz-rich pebble; exact identification is impossible from the image alone

Mixed polished rock/mineral specimens

Indeterminate from image; likely quartz-bearing material with iron-oxide staining and possibly mica-rich schist

Small pale mineral/rock fragment

Indeterminate; possibly weathered quartz, calcite, or light-colored limestone

Unidentified Small Rock

Unknown

Tumbled light-colored stone, possibly quartz or agate

Undetermined; likely microcrystalline quartz (SiO₂)

Likely dark mineral or rock fragment

Indeterminate from image; possibly a dark silicate mineral such as hornblende, biotite, or basalt

Small brown pebble or mineral fragment

Indeterminate from image; possibly iron-stained quartz, ironstone, or a dark mineral grain

Unidentified gray rock/mineral specimen

Indeterminate; possibly quartz-rich rock or a metallic sulfide-bearing specimen

Possible weathered sandstone or iron-rich sedimentary rock

Indeterminate; likely quartz-rich sandstone with iron-oxide cement

Small rounded light-colored mineral pebble

Indeterminate; possibly quartz, feldspar, or calcite

Rounded river pebble, likely quartz-rich sandstone or fine-grained granite

Indeterminate from photograph; possible quartz/feldspar-bearing granitic pebble

Fossilized bone fragment

Permineralized vertebrate bone, likely mammalian or reptilian; exact identification requires microscopy

Dyed or synthetic turquoise-blue glass-like specimen

Likely man-made colored glass or resin; exact identification requires testing

Milky quartz (with iron-oxide staining)

Quartz, silicon dioxide (SiO₂)

Likely limestone or calcareous fossil fragment

Calcite-rich carbonate rock; possibly bioclastic limestone (CaCO₃)

Iron-rich meteorite candidate

Probable stony-iron or iron meteorite; exact classification requires testing

Unidentified gray mineral/rock fragment

Indeterminate from image; possibly quartz-rich material or mica-bearing schist

Fossil bone fragment

Fossilized vertebrate bone; exact taxon undetermined

Likely black beach pebble

Undetermined; possibly basalt, chert, or dark slate

Tumbled blue glassy mineral specimen, possibly blue calcite or dyed quartz

Uncertain from image; likely calcite (CaCO₃) or dyed microcrystalline quartz (SiO₂)