Not A Rock Or Mineral (Anthropogenic Material)

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Ironstone with Pyrite

Ferruginous Sandstone (Fe2O3) with minor Sulfide minerals (FeS2)

Ferruginous Conglomerate

Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))

Goldstone (with Tiger's Eye and Quartz)

Aventurine glass (Synthetic SiO2 with Cu inclusions)

Gabbro

Plutonic mafic rock

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Basalt

Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)

Brick

Fired clay or Ceramic material (no specific mineralogical scientific name as it's a composite)

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Chert (Flint)

Chert (SiO2)

Greenstone / Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)

Conglomerate

Conglomerate (clastic sedimentary rock)

Dacite

Dacite (Intermediate volcanic rock)

Granite

Phaneritic Plutonic Igneous Rock

Jasper / Chert (River Pebble)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

River Quartzite (River Rock)

Quartzite (SiO2)

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Shale or Argillite

Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)

Jasper

Silicon dioxide (SiO2)

Chert (Commonly known as Flint)

Microcrystalline Quartz (SiO2)

Flower Jasper

Agatized Fossil Coral / Chalcedony (SiO2)

Banded Chert (River Stone)

Silicon Dioxide (SiO2)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diorite (with Iron Staining)

Phaneritic Intermediate Igneous Rock

Quartzite

Quartzite (SiO2)

Conglomerate (River Rock)

Clastic sedimentary rock (primarily SiO2)

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Chert (potentially Flint or Mudstone)

Microcrystalline Quartz (SiO2)

Diorite

Phaneritic Intermediate Plutonic Rock (Diorite)

Nuummite

Nuummite (Orthoamphibole rock / Anthophyllite-Gedrite blend)

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Decomposed Granite

Grano-diorite/Granite-residuum (SiO2 primary)

Greenschist

Greenschist facies rock (containing chlorite, actinolite, albite, and epidote)

Petrified Wood

Silicified Wood (SiO2)

Chert (Brecciated or Veined)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Yellow/Tan)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Sandstone (Red Flagstone)

Clastic sedimentary rock (primarily Quartz - SiO2)

Breccia

Breccia (Clastic Sedimentary Rock)

Basalt

Africite (Mafic Igneous Rock)