Mineralogical Simulant

Sandstone masonry blocks

Clastic sandstone, primarily quartz (SiO₂) with feldspar and lithic grains

Likely graphite-rich schist

Graphitic schist; chiefly graphite and quartz/mica

Porphyritic polymictic breccia (likely volcanic breccia)

Volcanic breccia; probable polymictic andesite–dacite breccia with quartz/feldspar clasts

Granite

Intrusive Igneous Rock

Hematite

Iron(III) oxide (Fe2O3)

Onyx (Calcite Onyx / Mexican Onyx)

Calcium Carbonate (CaCO3)

Likely polished leopard-skin jasper or brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the image alone

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

Dark mafic rock, possibly basalt or altered gabbro

Basaltic rock; commonly composed of plagioclase feldspar, pyroxene, and possibly olivine or iron oxides

Earthy iron-rich clay or weathered laterite

Hydrated iron oxides and clay minerals, commonly goethite/hematite with kaolinite or illite

Dark metamorphic rock, likely biotite schist or hornblende-bearing gneiss

Probable mica schist/amphibolite; composition may include biotite, amphibole, quartz, feldspar, and iron oxides

Weathered quartz-rich rock, likely quartzite or milky-quartz vein material

Quartzite (dominantly SiO₂), possibly quartz-vein breccia with iron-oxide staining

Iron-stained quartz-rich rock, likely pegmatite or quartz vein fragment

Quartz (SiO₂) with feldspar, mica, and iron-oxide/hydroxide staining; possibly weathered granite pegmatite

Howlite

Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)

Faceted blue gemstone ring, likely synthetic spinel or glass; identity uncertain

Possibly synthetic blue spinel (MgAl₂O₄) or laboratory sapphire (Al₂O₃); the clear side stones may be cubic zirconia or glass

Tumbled purple rock, likely lepidolite-bearing mica schist

Lepidolite-rich mica schist; lepidolite K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂, possibly mixed with quartz and feldspar

Weathered, rounded polymictic pebble (likely volcanic or metamorphic rock)

Indeterminate; possibly altered basalt, greenstone, or epidote-bearing metamorphic rock

Small rounded pebble

Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion

Quartz-rich metamorphic rock (probable quartzite)

Quartzite; predominantly crystalline SiO₂, with possible mica and iron-oxide impurities

Weathered mafic rock, likely basalt

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine and iron oxides

Small rounded orange-brown stone, likely iron-stained quartzite or sandstone

Indeterminate; probable quartz-rich sandstone/quartzite with iron-oxide staining

Chert (Green River Chert)

Microcrystalline Quartz (SiO2)

Dark mafic rock, likely basalt

Basalt; predominantly plagioclase feldspar and pyroxene, with possible olivine and iron-titanium oxides

Red gemstone ring, likely synthetic ruby or red spinel

Ruby: corundum (Al₂O₃); spinel: MgAl₂O₄; exact identity requires testing

Weathered sandstone block

Quartz-rich sandstone, likely arkose or calcareous sandstone

Diamond (in jewelry)

Carbon (C)

Polished orbicular granite (likely K2-type granite)

Granite, chiefly quartz, alkali feldspar, plagioclase, and dark amphibole/biotite; possible epidote-rich orbicules

Granite-like rock

Felsic intrusive igneous rock, probably granitic or granodioritic

Mica Schist (with Golden/Biotite inclusions)

K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)

Diamond (Set in jewelry)

Cubic Carbon (C)

Iron-rich concretion or weathered ironstone nodule

Goethite–hematite-rich limonite concretion (tentative)

Diamond (appearing in jewelry)

Diamond (pure Carbon, C)

Tumbled serpentinite (likely)

Serpentinite; chiefly antigorite/lizardite/chrysotile, Mg3Si2O5(OH)4, with accessory magnetite and possibly chromite

Weathered iron-rich rock, possibly basalt or ironstone

Indeterminate; likely Fe-oxide-bearing basaltic rock (commonly magnetite/hematite in a silicate matrix)

Sapphire

Corundum (Al2O3)

Dark slate or fine-grained metamorphic rock

Slate; chiefly fine-grained phyllosilicates, quartz, and feldspar

Dark mafic rock, likely basalt with iron-oxide veining

Basalt; predominantly plagioclase and pyroxene, possibly olivine, with hematite/goethite staining

Weathered sandstone or siltstone

Clastic sedimentary rock, chiefly quartz and feldspar grains cemented by silica, iron oxides, or carbonate

Greenstone (likely altered basalt or greenschist)

Greenschist-facies mafic rock; commonly chlorite–actinolite–albite ± epidote, or chlorite-altered basalt

Small rounded pebble, likely limestone or quartz-rich sedimentary fragment

Indeterminate lithic clast; probable micritic limestone (CaCO₃) or weathered quartz-rich stone

Weathered mineralized rock fragment

Indeterminate; likely quartz–feldspar-rich lithic material with iron-oxide staining

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, potentially granitic or quartzitic material