Biogenic Material

Petrified Wood

Silicified Wood (SiO2)

Blue polished cabochon, likely dyed agate or chalcedony

Chalcedony (microcrystalline quartz, SiO₂); exact material cannot be confirmed from the image

Serpentinite with green serpentine inclusion

Serpentinite; serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile, with possible magnetite

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Red jasper flake/tool blank

Jasper, microcrystalline quartz (SiO₂), colored by iron oxides

Coquina

Coquina (Bioclastic Limestone)

Tumbled quartz or chalcedony (uncertain)

Quartz, SiO₂; possibly cryptocrystalline chalcedony

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (Quartz arenite / Arkose)

Schist

Mica Schist

Iron-rich concretion or weathered ironstone pebble

Goethite/limonite-bearing ironstone; commonly an iron-oxide concretion (FeO(OH)·nH₂O, variable)

Slate

Slate (Foliated metamorphic rock)

Tumbled blue-dyed stone, likely basalt or blue aventurine

Likely fine-grained basalt (plagioclase and pyroxene), possibly coated or dyed; exact identification requires testing

Glass

Amorphous Silicon Dioxide (SiO2)

Weathered stone nodule or concretion

Unidentified lithic concretion; composition cannot be determined from the image

Chert (Arrowhead Fragment)

Cryptocrystalline quartz (SiO2)

Green cabochon, likely dyed or imitation material

Undetermined; the image is insufficient to identify a mineral species

Goldstone

Aventurine Glass (Man-made)

Ferruginous Sandstone (Ironstone Conglomerate fragments)

Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)

Zebra Jasper

Tetragonal Silicon Dioxide (Quartz) with impurities

Tumbled tiger’s eye

Quartz (SiO₂) with fibrous riebeckite/crocidolite inclusions

Polished ocean jasper (orbicular jasper)

Jasper, microcrystalline quartz (SiO₂), commonly with iron oxides and chalcedony

Polished Porcelain Jasper

Jasper (microcrystalline quartz, SiO₂), commonly sold as Porcelain Jasper

Polished agate/geode slab

Banded chalcedony (microcrystalline quartz, SiO₂), likely with quartz crystals

Diamond

C

Chert (Flint)

Sedimentary Cryptocrystalline Quartz (SiO2)

Diamond (or Diamond Simulant like Cubic Zirconia)

Carbon (C) - if Diamond; Zirconium dioxide (ZrO2) - if Cubic Zirconia

Chrysoprase-bearing serpentine (probable)

Serpentine-group minerals, mainly lizardite/antigorite, with possible nickel-bearing chrysoprase or green garnierite

Quartz Sand

Silicon Dioxide (SiO2)

Crushed Limestone

Calcium Carbonate (CaCO3)

Quartz vein material

Quartz (SiO₂), likely milky quartz with iron-oxide staining

Jasper or Agatized material

Microcrystalline Quartz (SiO2)

Likely a small rough mineral specimen

Unidentifiable from the image; possibly a mica-bearing rock or green mineral

Engineered Quartz

Engineered Stone (primarily SiO2)

Fossiliferous Sandstone / Fossil Fragment

Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material

Fossiliferous limestone pebble

Bioclastic limestone, commonly calcitic (CaCO₃)

Polished pale chalcedony or quartz pebble

Microcrystalline quartz, SiO₂; possibly milky quartz/chalcedony

Iron-rich sandstone or weathered laterite

Ferruginous sandstone, composed mainly of quartz with iron-oxide cement (Fe₂O₃/FeOOH)

Weathered quartz-rich rock, possibly quartzite or silicified sandstone

Quartzite (predominantly microcrystalline quartz, SiO₂); precise identification requires testing

Amphibolite

Hornblende–plagioclase amphibolite

Tumbled granite (likely granodiorite)

Granite–granodiorite aggregate, chiefly quartz, feldspar, and biotite/hornblende