Not A Geological Specimen

Weathered granite (probable)

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz and feldspar, with dark mica or amphibole

Iron-rich lateritic rock (ironstone)

Goethite–hematite-rich ferruginous material; exact identification requires testing

Fossiliferous Limestone

Biomicrite / Limestone with fossils

Small gold-colored jewelry piece with clear stones

Likely a metal setting holding small faceted gemstones; the stones cannot be identified from the image.

Limonite (Ironstone)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

Unidentified rough rock fragment

Indeterminate; the image does not show enough detail for a reliable mineral or rock identification

Clear faceted gemstone in an ornate ring (likely quartz or glass imitation)

Unidentified colorless faceted stone; visual identification is inconclusive

Blue sea glass or blue glassy mineral fragment

Uncertain; likely man-made soda-lime glass, not a natural mineral

Likely beach-worn glass and a pebble

The brown piece appears to be weathered glass (amorphous SiO₂-rich material); the pale piece is likely a small quartz-rich stone, possibly milky quartz.

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Likely biotite-rich schist

Mica schist, composed chiefly of biotite and quartz; exact identification is uncertain from the image.

Likely slate or fine-grained metamorphic rock

Slate; predominantly microscopic mica, quartz, and clay-derived minerals

Unidentifiable embedded dark fragment

Indeterminate; possibly a dark silicate mineral or lithic inclusion

Weathered limestone

Limestone; predominantly calcite (CaCO₃)

Banded Gneiss

Gneiss

Moqui Marble (Iron-Oxide Concretion)

Iron Oxide Concretion (Fe2O3)

Likely coral fragment or porous limestone

Calcareous biogenic carbonate, primarily calcite (CaCO₃); exact identification is uncertain from the image

Biotite-rich granite or granitic gneiss

Granite; quartz–feldspar–biotite assemblage

Dendritic limestone or marble slab

Manganese-oxide dendrites in carbonate rock, likely calcite (CaCO₃)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Iron-rich laterite (hematitic limonite)

Laterite composed mainly of hematite (Fe₂O₃), goethite (FeO(OH)), and hydrated iron oxides

Banded Iron Formation (BIF)

Banded Iron Formation (predominantly Hematite Fe2O3 and Magnetite Fe3O4 with Chert SiO2)

Crinoid Columnal Fossil in Chert

Crinoidea stemming section in Microcrystalline Quartz (SiO2)

Brain Coral Fossil

Family Mussidae or Merulinidae (Order Scleractinia)

Green aventurine cabochon earrings

Aventurine quartz (SiO₂), likely green quartzite with fuchsite mica

Amethyst bead bracelet

Amethyst, purple quartz (SiO₂)

Ironstone Concretion (Moqui Marble)

Iron-oxide Concretion (Hydrated ferric oxide, Fe2O3·nH2O)

Amygdaloidal Basalt

Basalt (with filled vesicles/amygdules)

Veined quartz-bearing metamorphic rock

Likely quartzite or quartz-veined hornfels; exact identification requires a fresh surface and tests

Weathered iron-rich sandstone or ironstone concretion

Ferruginous sandstone; chiefly quartz (SiO₂) cemented by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Goethite / Limonite Concretion

Iron Hydroxide Oxide (FeO(OH))

Weathered schist or gneiss cobble

Foliated silicate rock, likely mica schist or biotite gneiss

Metal Alloy (Jewelry)

Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Potassium Feldspar, and Mica)

Kimberlite

Kimberlite (Porphyritic Peridotite)

Weathered iron-rich limestone or calcareous sandstone

Calcite-rich carbonate rock, possibly ferruginous limestone (CaCO₃ with iron oxides)

Iron-rich sandstone (ferruginous sandstone)

Quartz-rich sandstone cemented by iron oxides, chiefly hematite (Fe₂O₃) and/or goethite (FeO(OH))

Limonite

FeO(OH)·nH2O (Hydrated iron oxide)

Mica Schist

Mica Schist (composed mainly of Muscovite / Biotite, Quartz, and Feldspar)

Septarian Nodule (Dragon Stone)

Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)

Fossilized Syringopora Coral (Organ Pipe Coral Fossil)

Syringopora sp. (Class Anthozoa, Order Tabulata)