Mixed (Predominantly Sedimentary And Igneous)

Tumbled jasper or chert pebble

Microcrystalline quartz (SiO₂), likely jasper/chert with iron-oxide staining

Granite (Pink/Potassium Feldspar Granite)

Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)

Granite (weathered fragment)

Granite; chiefly quartz, alkali feldspar, plagioclase, and mica

Volcanic breccia or conglomeratic volcanic rock

Lithic volcanic breccia; possibly andesitic–basaltic matrix with feldspar-rich clasts

Weathered granite or granitic rock fragment

Granite; chiefly quartz, feldspar, and mica

Quartz-rich conglomeratic breccia

Polymictic clast-supported conglomerate/breccia, dominated by quartz and feldspar

Rounded, weathered rock (likely quartz-rich granite or gneiss)

Undetermined quartz–feldspar-rich rock; precise identification requires closer examination

Porphyritic granite pebble

Granite, chiefly quartz (SiO₂), alkali feldspar and plagioclase, with minor biotite/hornblende

Granitic Quartz or Pegmatite

Quartz with Orthoclase Feldspar (SiO2 + KAlSi3O8)

Snowflake Obsidian (possibly mixed with Jasper or other matrix)

Obsidian with Cristobalite inclusions

Mixed landscaping gravel with a pink granite cobble

Primarily granite (quartz, alkali feldspar, plagioclase, biotite); mixed pebble assemblage

Mixed rounded stream pebbles

Most appear to be granitic and mafic igneous rocks, including granite, gneiss, basalt, and possibly quartzite; exact identification is uncertain from the image.

Dalmatian Jasper

Microcrystalline Quartz with Arfvedsonite/Tourmaline inclusions

Pyrite-bearing sulfide specimen (likely pyrite)

Pyrite, FeS₂; possibly mixed with pyrrhotite or chalcopyrite

Weathered sandstone or granitic rock fragment

Indeterminate siliciclastic rock; likely quartz–feldspar–mica aggregate

Likely weathered limestone

Calcite-rich limestone (mostly CaCO₃), possibly dolomitic limestone

Mixed rock and mineral specimens

Multiple unidentified silicate rocks and minerals; likely quartz-bearing material, feldspar, mica, and iron-oxide-bearing stones

Polished brecciated jasper bracelet

Jasper, microcrystalline quartz (SiO₂), commonly with hematite and iron-oxide inclusions

Mixed rock fragments, likely basalt and weathered granite

Basalt (mafic volcanic rock) and granitic fragments (quartz–feldspar–mica aggregate)

Conglomerate (pebble conglomerate)

Clastic sedimentary rock composed of rounded gravel-sized clasts in a finer matrix

Mixed tumbled quartz specimens

Quartz, silicon dioxide (SiO₂), including rose quartz and milky/included varieties

Milky quartz (likely quartz-rich rock fragment)

Quartz, silicon dioxide (SiO₂)

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica, with iron-oxide weathering

Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)

Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)

Mixed rounded gravel and weathered rock fragments

Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts

Leopard Skin Jasper

Silicon Dioxide (SiO2) with impurities

Botryoidal hematite (specular/earthy hematite)

Hematite, Fe₂O₃

Mixed river-worn rock collection

Uncertain; likely quartzite, sandstone, basalt, and weathered granite or gneiss

Biotite granite (likely weathered granite)

Granite; quartz + feldspar + biotite, with accessory dark minerals

Weathered polymictic gravel/conglomeratic rock

Polymictic conglomerate or poorly lithified alluvial gravel; chiefly quartz, feldspar, mica, and dark lithic fragments

Weathered conglomeratic breccia

Polymictic conglomerate/breccia, likely iron-stained

Graywacke sandstone (probable)

Lithic graywacke; composition commonly quartz, feldspar, lithic fragments, and clay-rich matrix

Tumbled jasper or chert pebble

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chert

Petrified Wood and Mixed Rocks

Silicified Wood (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Chrysocolla

Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)

Sapphire

Corundum (Al2O3)

Rounded conglomeratic river pebble

Polymict conglomerate (lithified gravel), composition uncertain from image

Rounded gray stone, likely weathered chert or quartz-rich river pebble

Chert (microcrystalline SiO₂), tentative

Rounded sandstone cobble

Quartz-rich sandstone, likely arkosic or lithic sandstone

Mixed tumbled stones, likely rose quartz and purple quartz/amethyst

Quartz (SiO₂), including amethyst and probable rose quartz; exact identification is uncertain from the blurred image

Tumbled quartz-rich stone, possibly granite or rhyolite

Likely quartz (SiO₂) with feldspar and minor mica or other inclusions