Industrial Byproduct (Anthropogenic Rock Like Material)

Epidote with Feldspar/Quartz (Unakite-like)

Epidotized Granite (Ca2(Al,Fe)3(SiO4)3(OH) + KAlSi3O8)

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

White Agate (Chalcedony)

Silicon Dioxide (SiO2)

Schist with Schorl (Black Tourmaline)

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

Sandstone

Arenite

Man-made Synthetic Material (Not a rock or mineral)

Polyester (Polyethylene terephthalate) / Faux Fur

Variscite (or potentially a turquoise/variscite matrix cabochon, or an impression jasper)

AlPO4·2H2O (Variscite) or related phosphate/silicate material depending on exact composition

Quartz (Milky/Crystalline)

Silicon Dioxide (SiO2)

Granite

Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

Quartzite

Quartzite (SiO2)

Yellow Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Black Obsidian

Volcanic Glass (predominantly SiO2, Silicon Dioxide)

Sandstone

Clastic Sedimentary Rock (composed mostly of SiO2)

Quartz Vein with Host Rock (Greywacke/Siltstone)

Silicon Dioxide (SiO2) within Clastic Sedimentary/Metamorphic Matrix

Sandstone

Arenite (composed primarily of SiO2)

Diorite

Diorite (Intermediate intrusive igneous rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Limestone

Calcareous sedimentary rock (primarily Calcium Carbonate, CaCO3)

Sandstone (with possibly iron oxides and other minerals)

Sandstone

Yellow Quartz (Citrine Quartz Pebble)

Silicon Dioxide (SiO2)

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Goldstone (with Tiger's Eye and Quartz)

Aventurine glass (Synthetic SiO2 with Cu inclusions)

Chert Nodule in Limestone

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3)

Rough Diamond

Pure Carbon (C)

Meteorite (Chondrite)

Stony Meteorite (Ordinary Chondrite)

Mica Schist

Medium-grade regional metamorphic rock (composition varies)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Quartz

Quartz (SiO2 - Silicon Dioxide)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Larimar

Pectolite [NaCa2Si3O8(OH)] with copper substitution

Rutilated Quartz

SiO2 with TiO2 inclusions

Milky Quartz

Quartz (SiO2) with iron staining

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Ferruginous Oxides

Druzy Quartz

Silicon Dioxide (SiO2)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Sandstone (Pebble)

Sandstone (arenite, arkose, wacke depending on composition)

Yellow Ochre / Limonite

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Bituminous Coal

Organic-rich sedimentary rock (Complex hydrocarbons)

Digital Multimeter (Synthetic Object)

Digital Multimeter (DMM)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)