Mineraloid

Granite

Phaneritic plutonic rock (approx. 20-60% quartz, 35-90% feldspar)

Pink Granite

Potassium Feldspar-Rich Granite

Granite

Granite (Alkali-feldspar, Quartz, and Plagioclase composition)

Orbicular jasper

Orbicular jasper (microcrystalline quartz/chalcedony with iron-oxide and volcanic inclusions)

Tumbled yellow quartz-rich stone, likely yellow jasper or quartzite

Jasper/quartzite; mainly microcrystalline quartz (SiO₂), with iron-oxide staining

Tumbled serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile)

Quartz-rich breccia or vein quartz with iron staining

Microcrystalline to crystalline SiO₂, likely quartz with iron oxides/hydroxides and altered host rock

Weathered quartz-rich pebble

Likely granitic or feldspathic clast; chiefly quartz (SiO₂) and feldspar

Granite

Intrusive Igneous Rock

Granite

Intrusive igneous rock

Granite

Intrusive Igneous Rock

Malachite-bearing copper ore

Malachite (Cu₂CO₃(OH)₂), likely mixed with chrysocolla, limonite, or native copper minerals

Polished orbicular jasper (likely kambaba or ocean jasper)

Silicified microcrystalline quartz/chalcedony with iron-rich inclusions; mainly SiO₂

Iron-rich sandstone (ferruginous sandstone)

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

Amphibolite (likely)

Amphibolite, composed mainly of hornblende-group amphibole and plagioclase feldspar

Iron-oxide-rich breccia or weathered ironstone

Hematite–goethite ironstone, likely brecciated and quartz-bearing

Rhyolite (possibly porphyritic and altered)

Volcanic felsic rock; primarily quartz, alkali feldspar, plagioclase, and volcanic glass, with iron-oxide alteration

Weathered iron-rich sandstone or ironstone cobble

Ferruginous sandstone/ironstone, chiefly quartz (SiO₂) cemented or stained by iron oxides and hydroxides

Dark mafic rock, likely basalt

Basalt; primarily plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Unakite (likely, rough specimen)

Epidote–feldspar–quartz rock; commonly approximated as pink orthoclase + green epidote + quartz

Yellow serpentine (likely lemon chrysoprase/serpentine breccia)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly mixed with magnesite and iron oxides

Dark gray fine-grained rock, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, often with minor olivine and magnetite

Weathered iron-rich rock (probable laterite or limonite-bearing stone)

Goethite–limonite mixture, commonly written FeO(OH)·nH₂O, with possible quartz and clay minerals

Tumbled greenstone (probable serpentinite)

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with chlorite, magnetite, or talc

Tumbled green-brown stone, likely serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite

Tiny rounded brown mineral grain

Indeterminate; possibly iron oxide, garnet, or a weathered sulfide grain

Veined metamorphic cobble, likely serpentinite

Serpentinite, commonly dominated by antigorite/lizardite with magnetite and cross-cutting quartz or calcite veins

Blue-gray tumbled stone, likely labradorite or blue-gray feldspar

Plagioclase feldspar, possibly labradorite (NaAlSi₃O₈–CaAl₂Si₂O₈)

Iron-rich laterite or weathered ironstone pebble

Goethite–hematite-rich ferruginous duricrust; commonly approximated as FeO(OH) and Fe₂O₃

Flint or chert fragment

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Weathered iron-rich rock, likely magnetite-bearing basalt or ironstone

Basalt/ironstone mixture dominated by iron oxides, chiefly magnetite (Fe3O4) and hematite (Fe2O3)

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly with mica or feldspar

Fossilized shell, likely brachiopod or bivalve

Indeterminate fossil shell; possible Spiriferida brachiopod or thick-shelled bivalve

Tumbled azurite–malachite or blue jasper (tentative)

Likely azurite-bearing copper mineral aggregate; composition commonly Cu₃(CO₃)₂(OH)₂ with associated malachite Cu₂CO₃(OH)₂

Weathered foliated metamorphic rock, likely schist or gneiss

Micaceous quartz–feldspar metamorphic rock; exact mineralogy requires testing

Metallic sulfide-bearing metamorphic rock

Likely graphitic schist or sulfide-rich schist, with possible pyrite/arsenopyrite and mica

Unidentified rounded mineral/rock fragment

Indeterminate; likely a weathered quartz-rich stone or iron-stained granite fragment

Gneiss

Gneiss

Unidentified gray weathered rock

Possibly weathered granite or granitic gneiss; exact identification requires a fresh surface and tests

Granite

Granite (Felsic Plutonic Rock)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Banded slate or phyllite

Fine-grained foliated metasedimentary rock; likely slate with light-colored quartz veins