Man Made Material

Dark flint or chert fragment

Microcrystalline quartz (SiO₂), likely flint/chert

Actinolite (likely fibrous amphibole)

Actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂; possibly an actinolite–tremolite specimen

Likely milky quartz with iron-oxide inclusions

Quartz, silicon dioxide (SiO₂)

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with iron oxide cement)

Tumbled carnelian agate with dark mineral inclusions

Carnelian, an orange variety of microcrystalline quartz (chalcedony), SiO₂; dark inclusions are likely iron oxides/hydroxides, possibly hematite, goethite, or a basaltic/matrix fragment

Yellow tumbled/rough chalcedony, possibly citrine or dyed agate

Chalcedony (microcrystalline SiO₂), with yellow coloration likely from iron oxides; exact identification is uncertain from the photograph

Quartz

Quartz (SiO₂)

Iron-stained quartz-rich rock, possibly goethite-bearing quartz

Quartz (SiO₂) with iron oxides/hydroxides, likely goethite or limonite

Granite

Intrusive Phaneritic Felsic Igneous Rock

Blue chalcedony cabochon (probable)

Chalcedony, cryptocrystalline quartz; silicon dioxide (SiO₂)

Chrysotile Asbestos

Chrysotile [Mg3Si2O5(OH)4]

Granodiorite

Granodiorite

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)

Flint or chert

Microcrystalline quartz (SiO₂), commonly with chalcedony

Iron-rich laterite or limonite/goethite-bearing rock

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O), likely in a lateritic matrix

Sandstone

Arenicola (comprising mostly Quartz, SiO2)

Tumbled blue-green stone, likely chrysocolla or dyed chalcedony

Probable chrysocolla (hydrated copper aluminosilicate; variable composition), though appearance could also represent dyed chalcedony

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Tumbled green aventurine (probable)

Quartzite dominated by quartz (SiO₂), with green mica/fuchsite or chlorite inclusions

Chert (also known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Conical fossil shell or shell fragment

Likely a gastropod shell fragment; exact taxon indeterminate from the image

Tumbled serpentine

Serpentinite; chiefly antigorite, lizardite, and/or chrysotile [Mg₃Si₂O₅(OH)₄]

Limestone

Calcium Carbonate (CaCO3)

Granite

Phaneritic Felsic Igneous Rock

Sandstone (likely Fossiliferous)

Arenite / Sedimentum arenaceum

Yellow chalcedony (likely heat-treated or resin-coated)

Microcrystalline quartz, SiO₂

Sandstone Chert/Quartzite

Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite

Diamond

Carbon (C), specifically a solid form of the element carbon with atoms arranged in a crystal structure called diamond cubic.

Quartz (likely Milky Quartz)

Quartz (SiO₂ - Silicon Dioxide)

Laterite

Laterite (primarily composed of hydrated oxides of iron and aluminum)

Sandstone

Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)

Weathered granite (feldspathic, iron-stained granite)

Granite; primarily quartz, potassium feldspar, plagioclase feldspar, and minor mica/amphibole. Exact identification is uncertain from a single photograph.

Fossil gastropod shell

Fossilized marine gastropod; exact genus/species requires locality and examination

Dark gray basalt or andesite cobble

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase feldspar, pyroxene, and possibly olivine

Possible tektite or iron-rich slag-like natural specimen

Uncertain; possibly natural glass (tektite) or magnetite-rich rock

Seraphinite

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

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Red Jasper or Chert

Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)

Likely serpentine (serpentinite) pebbles

Serpentine-group minerals, chiefly antigorite, lizardite, and/or chrysotile; commonly Mg₃Si₂O₅(OH)₄, sometimes containing magnetite, chromite, and minor carbonate minerals

Quartz vein rock with iron-stained matrix

Quartz (SiO₂), likely with limonite/goethite and minor feldspar or mica

Veined Quartz

SiO2 (Silicon Dioxide)

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)