Indeterminate

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

Unidentified weathered mineral/rock fragment

Indeterminate; likely a weathered iron-rich silicate or sulfide-bearing specimen

Fossiliferous limestone with a possible shell or trace fossil

Calcitic limestone (mostly CaCO₃), fossil identity indeterminate from the image

Likely brown quartz-rich rock or iron-stained mineral specimen

Indeterminate; possibly iron-stained quartz (SiO₂) with limonite/goethite coatings

Faceted purple-blue beads, likely synthetic glass or treated gemstone

Indeterminate; possible synthetic corundum, synthetic spinel, or dyed quartz (SiO₂)

Likely weathered fossil shell or fossiliferous limestone

Indeterminate molluscan fossil, possibly a bivalve or brachiopod preserved in carbonate rock

Weathered quartz-bearing rock, possibly granite or gneiss

Indeterminate; likely quartz–feldspar–mica aggregate, possibly granitic gneiss

Fossilized shell fragment

Likely calcitic or aragonitic bivalve/gastropod shell; exact taxon indeterminate

Unidentified small rounded mineral/rock fragment

Indeterminate from image; possibly quartz or chalcedony with iron-oxide staining

Small rough mineral specimen, likely quartz-bearing stone

Indeterminate from image; possibly quartz (SiO₂) with iron-oxide staining

Rounded river cobble, likely quartz-rich sandstone or quartzite

Indeterminate quartz-rich clastic rock; probable sandstone (SiO₂-rich)

Small rounded orange-brown stone, likely iron-stained quartzite or sandstone

Indeterminate; probable quartz-rich sandstone/quartzite with iron-oxide staining

Weathered quartz-rich rock, possibly granite or quartzite

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

Likely weathered sandstone or limestone pebble

Indeterminate sedimentary rock; possibly quartz-rich sandstone or calcitic limestone

Rounded river pebble, likely weathered sandstone or volcanic rock

Indeterminate fine-grained lithic clast; possible sandstone (quartz-rich)

Fossil bivalve shell

Fossilized marine bivalve; exact genus/species indeterminate from the photograph

Fossil brachiopod or bivalve shell

Indeterminate fossilized shell; likely a ribbed brachiopod (Order Productida or Spiriferida)