Mineralogical

Likely serpentine-rich ultramafic rock

Serpentinite; chiefly serpentine-group minerals (Mg3Si2O5(OH)4), commonly with magnetite and relict olivine/pyroxene

Mica-rich metamorphic rock, likely schist

Muscovite–biotite schist, possibly with quartz and feldspar

Veined dark metamorphic rock, likely serpentinite

Serpentinite, predominantly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible quartz, calcite, and magnetite veins

Dark mafic rock, likely basalt

Basalt; mainly plagioclase feldspar, pyroxene, and commonly olivine or magnetite

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Weathered granite or granitic gneiss

Granite; chiefly quartz, feldspar, and mica/amphibole

Likely basalt (possibly iron-rich volcanic rock)

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

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

Iron-stained metamorphic rock, likely quartzite or jasper

Quartz-rich rock dominated by SiO₂, with iron oxides/hydroxides (hematite, goethite) and possible clay or mica

Polished orbicular granite (likely K2-type granite)

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

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

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

Tumbled quartz-rich pebble

Quartz (SiO₂), possibly iron-stained milky quartz or quartzite

Gold-bearing pyrite-rich rock (iron pyrite)

Pyrite, FeS₂, likely in a quartz- or sulfide-rich matrix

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

Schist

Schist (various mineralogical compositions including mica, chlorite, talc, etc.)

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)

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

Iron-rich weathered stone, possibly hematite-rich ironstone

Hematite/goethite-bearing ironstone; predominantly Fe₂O₃ and FeO(OH)

Rhodonite-bearing metamorphic rock

Manganese-rich metamorphic rock, chiefly rhodonite (MnSiO₃), with quartz and manganese oxides

Weathered granite pebble

Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole

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

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)

Likely weathered iron-rich sandstone or laterite

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

Iron-stained sandstone

Quartz arenite or lithic sandstone, variably cemented by iron oxides

Sapphire

Corundum (Al2O3)

Likely basalt pebble

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

Weathered sandstone block

Quartz-rich sandstone, likely arkose or calcareous sandstone

Small brown rock fragment

Undetermined; possibly weathered iron-stained quartzite or chert

Greenstone (probable altered basalt)

Chlorite–epidote–actinolite-rich greenschist; composition commonly derived from basalt

Pyrite-bearing quartz or sulfide-rich rock

Pyrite (FeS₂) in quartz-rich matrix, possibly with chalcopyrite

Drill Core Sample

Cylindrical Rock Core (Specific mineralogy varies by extraction site)

Weathered iron-rich concretion or breccia

Goethite/hematite-bearing limonite concretion, possibly ferruginous sandstone