Indeterminate

Small unidentified mineral specimen

Indeterminate from image; possibly a quartz-family crystal or sulfide mineral

Fossil plant impression slab

Fossilized plant compression/impression; exact taxon indeterminate from the image

Uncertain pale mineral/rock fragment

Indeterminate; possibly calcite-rich material or a light-colored carbonate rock

Fossil shell fragment

Likely fossilized bivalve or brachiopod; exact taxon indeterminate from the image

Likely quartz-rich pebble or weathered limestone fragment

Indeterminate; possibly microcrystalline quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Small translucent tumbled crystal or gemstone

Indeterminate; likely quartz (SiO₂), possibly citrine or glass-like chalcedony

Tumbled quartz-rich rock, possibly calcite or sandstone

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Fossil gastropod shell

Fossilized or mineral-replaced gastropod (class Gastropoda), exact genus indeterminate

Likely weathered quartz-rich rock fragment

Indeterminate; possibly quartz-bearing sandstone or chert with iron-oxide staining

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz-feldspar aggregate, potentially granitic or quartzitic material

Likely quartz-rich stone or pale feldspar fragment

Indeterminate; possibly quartz (SiO₂) or feldspar (KAlSi₃O₈–NaAlSi₃O₈)

Fossilized coral or stromatoporoid

Calcareous coral, likely an indeterminate fossil colonial coral (phylum Cnidaria)

Unidentified brown rock fragment

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

Tumbled beach pebble (likely quartz-rich sandstone or chert)

Indeterminate lithic clast; likely quartz (SiO₂)-rich sandstone/chert

Small conical fossil shell fragment

Indeterminate gastropod or scaphopod shell; likely calcium carbonate (aragonite/calcite)

Fossil fish impression or partial fish fossil

Indeterminate fossilized fish; likely compressed vertebrate remains in sedimentary rock

Weathered quartz-rich cobble (probable sandstone or quartzite)

Indeterminate; likely quartz arenite sandstone, possibly weakly metamorphosed quartzite

Likely tumbled black stone or glassy mineral

Indeterminate from image; possibilities include obsidian, hematite, or black tourmaline

Rounded pebble (likely quartz-rich sandstone or weathered chert)

Indeterminate from image; possibly quartz (SiO₂)-rich lithic material

Tumbled dark stone, possibly basalt or iron-rich chert

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or ferruginous chert

Fossil ammonite fragment

Ammonoidea (likely a small heteromorph or coiled ammonite; exact genus indeterminate)

Weathered quartz-rich rock, possibly quartzite or granite

Indeterminate; likely quartz–feldspar aggregate, possibly granitic gneiss or quartzite

Fossilized wood or bone fragment

Indeterminate permineralized organic fossil; possibly silicified wood or fossil bone

Weathered rounded stone, likely quartz-rich sandstone or granitoid

Indeterminate feldspathic quartz rock; possibly weathered granite or granitic gneiss

Weathered brown river pebble, likely sandstone or iron-rich quartzite

Indeterminate; probable quartz-rich sandstone (quartz and iron-oxide cement)

Rounded weathered stone, likely quartz-rich sandstone or fine-grained volcanic rock

Indeterminate hand specimen; probable quartz–feldspar sandstone (SiO₂-rich)

Tumbled cream-colored stone, possibly quartz or calcite

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

Fossil coral or stromatoporoid fragment

Likely fossilized colonial coral; exact taxon indeterminate from image

Tumbled golden-brown stone, likely sandstone or iron-stained quartzite

Indeterminate from image; probable quartz-rich sandstone (SiO₂) or quartzite

Weathered gray rock, possibly basalt or andesite

Indeterminate fine-grained volcanic rock; likely basaltic-andesitic composition

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially granitic, or recrystallized quartzite

Rounded river cobble, likely quartz-rich sandstone or quartzite

Indeterminate quartz-rich clastic rock; possibly quartzite (mostly SiO₂)

Fossilized bone fragment

Petrified bone, mineral-replaced vertebrate bone; exact taxon indeterminate

Likely quartz-bearing metamorphic pebble

Indeterminate; probable quartzite or quartz-rich gneiss with dark mica/amphibole

Likely quartz-rich rock fragment

Indeterminate; probably microcrystalline quartz (SiO₂) with minor feldspar or weathering minerals

Weathered iron-rich rock, possibly limonite-bearing quartzite or altered basalt

Indeterminate; likely quartz (SiO₂) with iron oxides/hydroxides such as limonite/goethite

Rounded river pebble, likely sandstone or weathered quartzite

Indeterminate lithic clast; probable quartz-rich sandstone (SiO₂-dominant)

Brown weathered river pebble

Indeterminate lithology; likely ferruginous sandstone, mudstone, or weathered volcanic rock

Tumbled cream-colored stone, possibly calcite or quartz

Indeterminate from image; likely calcite (CaCO₃) or milky quartz (SiO₂)

Weathered, rounded polymictic pebble (likely volcanic or metamorphic rock)

Indeterminate; possibly altered basalt, greenstone, or epidote-bearing metamorphic rock

Fossil shell impression or shell-bearing limestone

Indeterminate bioclastic carbonate; likely mollusk fragment preserved in limestone or mudstone

Unidentified metallic-looking mineral fragment

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