Mineral (Sedimentary Context)

Ferruginous Conglomerate

Ferruginous Conglomerate (Clastic Sedimentary Rock)

Granite

Granite (phaneritic intrusive felsic igneous rock)

Eudialyte in Matrix

Na15Ca6(Fe,Mn)3Zr3(Si,Nb)(Si25O73)(O,OH,H2O)3(Cl,OH)2

Ruby (in costume jewelry context)

Corundum (Al2O3) with Chromium impurities

Black Star Diopside

Diopside (CaMgSi2O6) with Magnetite inclusions

Likely tumbled quartz-bearing rock or glittery quartz specimen

Quartz, silicon dioxide (SiO₂), possibly included quartz or quartzite

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Iron-stained quartz vein rock

Quartz-rich vein material with iron oxides/hydroxides (quartz, SiO₂, stained by hematite/goethite); likely hosted in a metamorphic rock

Greenstone (Celadonite-bearing Volcanic)

Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Pink feldspar-bearing pegmatite

Orthoclase–microcline feldspar, chiefly KAlSi₃O₈, in a granitic pegmatite matrix

Amethyst (Tumbled/Weathered Quartz)

Amethyst (SiO2 with iron impurities)

Black Onyx

Black Chalcedony (SiO2)

Weathered basalt pebble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar, pyroxene, and commonly olivine

Dark slate (probable)

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz; exact identification is uncertain from the photograph.

Chert (often called Flint in this context)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Schist (Biotite/Mica Schist)

Medium-grade regional metamorphic rock (rich in Phyllosilicates)

Ferruginous Quartzite (also known as Ironstone or Gossan)

Ferruginous Quartzite with Goethite/Hematite staining

Chert (Flint)

Silicon Dioxide (SiO2)

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Greenstone

Greenschist (composed of chlorite, actinolite, and epidote)

Iron Slag

Anthropogenic Vitreous Silicate (Byproduct of Smelting)

Polished serpentine (likely greenstone)

Serpentine-group minerals, chiefly antigorite/lizardite: Mg₃Si₂O₅(OH)₄

Vesicular basalt (scoria-like volcanic rock)

Basalt, composed mainly of plagioclase, pyroxene, and olivine; abundant vesicles formed by trapped gas

Gold (Elemental Metal)

Gold (Au)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Serpentinite

Serpentinite (containing minerals of the Serpentine subgroup: Antigorite, Lizardite, and Chrysotile; formula (Mg,Fe)3Si2O5(OH)4)

Green Quartzite (Aventurine-like)

Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)

Fluorite (often referred to casually as 'Fluorspar' in industrial contexts)

Fluorite (CaF2)

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Opalite

Synthetic Glass, SiO2 base with metallic inclusions

Dark weathered igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Copper (native copper)

Native copper, Cu

Iron-stained quartz (possible citrine/vein quartz)

Quartz, SiO₂, colored by iron-oxide inclusions

Seraphinite

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

Weathered iron-rich rock, likely basalt or ironstone

Probable weathered basalt (mafic silicate rock); exact identification requires a fresh surface and testing

Slag

Anthropogenic Vitrophyre (Iron or Smelting Slag)

Chert (often called Flint in archaeological contexts)

Microcrystalline or cryptocrystalline Silica (SiO2)

Arsenopyrite in Quartz Matrix

Arsenopyrite (FeAsS) with Quartz (SiO2)

Chert (Jasper or Flint variant)

Chert (composed of microcrystalline quartz, SiO2)

Chert (often called Flint in archaeological contexts)

Silicon Dioxide (SiO2)

Granite

Granite (a common type of Felsic Intrusive Igneous Rock)