Man Made Material, Not A Natural Rock Or Mineral Specimen

Chert / Flint Jasper

Microcrystalline Quartz (SiO2)

Rounded sandstone pebble

Quartz-rich sandstone; commonly arkose or lithic sandstone

Smoky Quartz (Herkimer-style)

Silicon Dioxide (SiO2)

Quartz vein rock with iron-stained matrix

Quartz (SiO₂), likely with limonite/goethite and minor feldspar or mica

Smoky Quartz

Silicon Dioxide (SiO2)

Granodiorite (Gneissic texture)

Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)

Quartz-bearing volcanic rock, likely vesicular basalt

Basalt with secondary quartz (SiO₂) and possible zeolite/chalcedony infill

Weathered granite pebble

Granite, mainly quartz, feldspar, and mica; approximate composition SiO₂-rich continental crust

Granite River Rock

Phaneritic Felsic Igneous Rock (Granite)

Vesicular basalt (likely amygdaloidal basalt)

Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, clinopyroxene, and commonly olivine; vesicles are partly mineral-filled amygdules.

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Fulgurite

Fulgurite (Lechatelierite), amorphous SiO2

Polished agate geode

Chalcedony (microcrystalline quartz, SiO₂) with quartz druse crystals

Sandstone

Sedimentary Rock (Quartz Sandstone)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)

Granite Pebble with Quartz/Feldspar Vein

Intrusive Felsic Igneous Rock (Granite)

Garnet-bearing metamorphic rock, likely mica schist

Biotite–garnet schist; commonly includes quartz, feldspar, biotite, and almandine garnet

Granite cobble

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

Banded iron formation fragment (likely hematite–magnetite ironstone)

Banded iron formation; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and microcrystalline quartz (SiO₂)

Diamond

Carbon (C)

Red Sandstone

Arenite (Ferruginous Sandstone)

Shale or Argillite

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

Peridot gemstone pendant

Olivine, gem-quality forsteritic olivine (approximately (Mg,Fe)₂SiO₄)

Iron-stained quartz-rich rock, likely quartzite or silicified breccia

Quartz (SiO₂), possibly quartzite with limonite/goethite iron oxides

Banded Chert / Cryptocrystalline Quartz

Silicon Dioxide (SiO2)

Diamond

Diamond (pure Carbon, C)

Red Jasper with Quartz Vein

Microcrystalline Quartz (SiO2) with Hematite inclusions

Weathered gray metamorphic rock, likely phyllite or slate

Micaceous quartz–phyllosilicate rock; commonly quartz + muscovite/illite ± chlorite

Azurite-Malachite (often a mixed specimen)

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.

Cat's Eye Moonstone (Simulated/Synthetic or natural Cat's Eye Quartz/Glass)

There is no single scientific name. The appearance suggests either: Moonstone (feldspar group), Cat's Eye Quartz (SiO2), Apatite (Ca5(PO4)3(F,Cl,OH)), or most likely a synthetic material such as Fiber Optic Glass or 'Opalite' (a type of glass).

Granite

Granite (Phaneritic intrusive igneous rock)

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Granite

Granite (phaneritic felsic intrusive rock)

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Yellow Ochre (Limonite)

Limonite (FeO(OH)·nH2O)

Granite

Granite (Felsic Intrusive Igneous Rock)

Yellow Quartz (Citrine-colored Quartz Pebble)

Silicon Dioxide (SiO2)

Diorite (Gneissic)

Diorite

Fossil-bearing ironstone or weathered concretion

Indeterminate; likely ferruginous sandstone/concretion containing a partial fossil impression

Siltstone or Limestone Beach Pebble

Siltstone / Micritic Limestone

Diamond

C (Native Carbon)