Industrial By Product

Pumice

Pumice (extrusive volcanic rock)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Coarse-Grained Marble

Recrystallized Limestone (Major component: CaCO3)

Blue Kyanite in Quartz

Kyanite (Al2SiO5)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Tumbled pink calcite

Calcite (calcium carbonate, CaCO₃)

Chert / Flint

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Pumice

Pumice (Vesicular Felsic Igneous Rock)

Polished pink halite (Himalayan salt)

Halite (sodium chloride, NaCl)

Mixed river stones and gravel

Polymictic alluvial clasts; individual pieces may include quartzite, granite, basalt, sandstone, limestone, and slate

Chert / Flint

Cryptocrystalline quartz (SiO2)

Flint / Chert Pebble

Microcrystalline Quartz (SiO2)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Amethyst (Tumbled)

Amethyst (SiO2 with iron impurities)

Vesicular basalt (probable scoriaceous basalt)

Basalt, composed mainly of plagioclase feldspar, pyroxene, and commonly olivine

Quartz vein / massive quartz

Quartz (SiO₂), likely milky quartz with iron-oxide and possibly chlorite inclusions

Seraphinite

Clinochlore (Mg,Fe)5Al(AlSi3O10)(OH)8 - specific variety for Seraphinite due to its fibrous inclusions and chatoyancy.

Red Jasper

Jasper (Silicon Dioxide with iron oxide inclusions), SiO2

Vesicular basalt (likely weathered basaltic rock)

Basalt; predominantly plagioclase, clinopyroxene, olivine, and volcanic glass

Tumbled serpentinite

Serpentinite, composed chiefly of serpentine-group minerals (lizardite, antigorite, chrysotile), commonly with magnetite and chlorite

Weathered porphyritic pebble

Likely porphyritic volcanic rock, possibly andesite or rhyolite

Muscovite Schist

KAl2(AlSi3O10)(OH)2 (Muscovite) in Schist Matrix

Ammonite fossil in matrix

Fossilized ammonoid cephalopod; likely an ammonite such as Dactylioceras or a related Jurassic taxon

Likely weathered granite or granitic rock

Granite; quartz + feldspar + mica, compositionally variable

Tumbled basalt (likely basalt–feldspar/zeolite-bearing stone)

Basalt; predominantly plagioclase feldspar and pyroxene, with possible olivine or secondary alteration minerals

Likely quartz-bearing metamorphic pebble

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

Serpentine (likely serpentinite)

Serpentine-group minerals, chiefly antigorite/lizardite, commonly with magnetite and chlorite

Weathered granite pebble

Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole

Limonite / Goethite Ironstone Concretion

FeO(OH)·nH2O (Hydrated Iron Oxide)

Rounded river pebble, likely basalt or weathered andesite

Fine-grained mafic volcanic rock; commonly basalt, approximately plagioclase–pyroxene ± olivine

Granite

Phaneritic Igneous Rock (primarily SiO2, Al2O3, K2O, Na2O)

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Epidote (or Epidote-rich rock)

Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).

Botryoidal pyrite (likely with quartz or chlorite matrix)

Pyrite, FeS₂; botryoidal aggregate

Vesicular basalt (likely weathered volcanic scoria)

Basaltic scoria; primarily plagioclase, pyroxene, and olivine

Iron-rich volcanic rock, possibly hematite-bearing basalt

Basalt with iron oxides/hydroxides, chiefly hematite (Fe₂O₃) and possibly magnetite (Fe₃O₄)

Weathered basalt (likely amygdaloidal basalt)

Basalt; chiefly plagioclase feldspar and pyroxene, with possible olivine and iron oxides

Iron-stained quartz vein fragment

Quartz, SiO₂, with iron-oxide/hydroxide staining (likely goethite or limonite)