The Purple Specimen Is A Mineral (Amethyst); The White Specimen Is A Sedimentary Rock (Limestone Or Marble).

Chert / Flint (with Crinoid Stem Molds)

Microcrystalline Quartz (SiO2)

Dendritic Agate (specifically Orange/Tumbled)

Silicon Dioxide (SiO2) with Oxide Inclusions

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Granite Pebble

Granite

Quartz (Milky/Crystalline)

Quartz (Silicon Dioxide, SiO2)

Chert (Common Opal/Jasper variety)

Silicon Dioxide (SiO2)

Quartzite in Conglomerate

Clastic Sedimentary Rock with Silicon Dioxide (SiO2) inclusions

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Basalt with Amygdules

Amygdaloidal Basalt

Chert (River Pebble)

Microcrystalline silica (SiO2)

Dyed Agate

Chalcedony (Silicon Dioxide, SiO2)

Chert (Field Stone/Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Amethyst (Cabochon)

Silicon Dioxide (SiO2) with iron impurities

Quartz with impurities or Host Rock

SiO2 (Silicon Dioxide) with mixed silicates

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Celestite (Celestine)

Strontium sulfate (SrSO4)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Basalt with Calcite Veins

Basalt (containing CaCO3 inclusions)

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Sandstone (Quartzite-rich)

Clastic sedimentary rock (primarily SiO2)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Sandstone (Quartzose)

Arenite (Formula: SiO2 primary, with various cements)

Tanzanite

Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))

Quartz Geode (Unbroken)

Silicon Dioxide (SiO2)

Quartzite (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartz (River Stone)

Silicon Dioxide (SiO2)

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Amethyst (Quartz)

Amethyst (SiO2 with iron impurities)

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Quartz Geode

Silicon Dioxide (SiO2)

Stichtite in Serpentine (Atlantisite)

Mg6Cr2CO3(OH)16·4H2O (Stichtite) / Mg3Si2O5(OH)4 (Serpentine)

Green Jasper (with Quartz veining)

Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2

Chert (Arrowhead/Tool variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline quartz (SiO2)

Satin Spar (often marketed as Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Raw Diamond (Rough Uncut)

Diamond (C - pure carbon)

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Dyed and Metallic Coated Agate Geode

Silicon Dioxide (SiO2) with titanium/gold vapor deposition coating

Basalt (River Stone/Pebble)

Basalt (Extrusive Igneous Rock)

Fursuit (Synthetic Fur Specimen)

Canis anthropomorphus syntheticus