Industrial Byproduct (Anthropogenic Rock Like Material)

Dalmatian stone

Dalmatian jasper (commercial name); commonly spotted rhyolite or related feldspar-rich rock, not true jasper

Small dark pebble, possibly basalt

Unidentified fine-grained mafic rock; basalt is a tentative visual match

Quartz (Druzy on Matrix)

Silicon Dioxide (SiO2)

Unidentified brown rock fragment

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

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Vesicular Basalt or Scoria

Basalt (extrusive volcanic rock)

Sandstone (likely Siltstone or Mudstone)

Clastic sedimentary rock (primarily SiO2 with various oxides)

Schist

Mica Schist

Gravel and Sediment Sample

Mixed clastic sediment

Muscovite Mica (in Quartz matrix)

Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)

Pumice

Pumicite / Vesicular Rhyolite

Vesicular Basalt

Aphanitic Mafic Volcanic Rock

Quartz and Iron Oxide

Quartz (Silicon Dioxide, SiO2) with possible Limonite/Hematite inclusions

Polished dark stone, likely basalt or fine-grained mafic rock

Basalt (approximately; commonly plagioclase, pyroxene, and minor olivine/magnetite)

Laterite

Laterite (Iron and aluminum-rich residual rock)

Iron-stained quartz-rich rock

Likely quartz with iron-oxide staining; exact rock type cannot be determined from the photo

Vesicular Basalt

Aphanitic Mafic Igneous Rock (with Vesicular Texture)

Fossil oyster shell

Fossilized bivalve, likely Ostrea or a related oyster genus; calcite (CaCO₃) shell

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Chalcedony

Silicon dioxide (SiO2)

Tumbled jasper (possibly orbicular jasper)

Microcrystalline quartz, SiO₂; jasper is an opaque variety of chalcedony

Weathered iron-rich rock fragment

Likely limonite/goethite with hematite and iron-bearing silicates; exact identification requires testing

Pink Granite

Phaneritic Plutonic Igneous Rock (high K-feldspar)

Petrified Wood

Silicified Wood (SiO2)

Red Sandstone

Ferruginous Sandstone (SiO2 dominated with Fe2O3)

Tiger’s-eye fragment

Chatoyant quartz, SiO₂, with pseudomorphic iron-oxide fibers

Faceted purple gemstone, likely amethyst

Amethyst, purple variety of quartz (SiO₂)

Drupa or Druzy Quartz on Geode Fragment

Crystalline Silicon Dioxide (SiO2)

Mixed beach-stone and tumbled-glass collection

Predominantly uncertain rocks (likely basalt, granite, and quartz-bearing stones) with anthropogenic glass; one possible banded agate or jasper

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Sandstone (Weathered Pebble)

Arenite (SiO2 primarily)

Vesicular basalt (scoriaceous basalt)

Basalt, chiefly plagioclase feldspar and pyroxene with minor olivine; vesicles formed by trapped volcanic gas

Sandstone

Arenite (SiO2 with various cementing agents)

Rough Diamond

Diamond (Native Carbon, C)

Basalt with Peridotite Inclusion

Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith

Rounded gray river cobble, likely quartz-rich sandstone or weathered granite

Indeterminate; possible granitic or feldspathic cobble (quartz–feldspar–mica aggregate)

Chert / Yellow Jasper

Silicon Dioxide (SiO2)

Ceramic or Polished Stone Heart (Anthropogenic Material)

Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)

Petrified Wood

Silicified wood (SiO2)

Polished brecciated jasper (likely)

Brecciated jasper, an opaque microcrystalline quartz (SiO₂) with contrasting silica-rich fragments and matrix

Basalt

Aphanitic Mafic Igneous Rock

Tumbled jasper (likely brecciated or multicolored jasper)

Microcrystalline quartz/chalcedony, SiO₂; jasper is an impure, opaque variety