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

Puddingstone

Conglomerate (Indurated)

Fuchsite on Quartz

Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities

Agate (Thunderegg segment)

Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Clastic Sedimentary Rock (Iron-rich)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Quartz (Milky or Citrine-tinted)

Silicon Dioxide (SiO2)

Chert (with Lichen)

Microcrystalline Quartz (SiO2)

Amethyst (Variety of Quartz)

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement) SiO2

Granite

Phaneritic Felsic Igneous Rock

Amygdaloidal Basalt

Amygdaloidal Mafic Volcanic Rock (Basalt)

Clear Quartz

Silicon Dioxide (SiO2) / Rock Crystal

Bauxite

Bauxite (mixture of Hydrous Aluminum Oxides)

Chert (variant Flint)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Zebra Jasper

Silicon Dioxide (SiO2) with various inclusions

Chert (specifically Tan Chert or Flint)

Silicon Dioxide (SiO2)

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Peach Moonstone

Potassium Aluminum Silicate (KAlSi3O8)

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Chert (Nodule)

Microcrystalline Silica (SiO2)

Chert (specifically Gray/Black Chert)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Blue Onyx (Dyed Agate)

Cryptocrystalline Quartz (SiO2) with artificial pigment

Quartzite

Quartzite (SiO2)

Chert (varietal: Flint/River Pebble)

Cryptocrystalline Quartz (SiO2)

River Rock (Quartzite/Chert conglomerate)

Quartzite (SiO2)

Satin Spar (Gypsum)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Rock Crystal Quartz

Quartz (SiO₂)

Basalt with Sulfide/Pyrite inclusion

Aphanitic Mafic Igneous Rock (likely Basalt) with Pyrite (FeS2)

Granite Pebble

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Granite Pebble

Granite (Phaneritic Quartz-Feldspar intrusive rock)

Green Calcite

Calcium Carbonate (CaCO3)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Crinoid Marble (Fossilized Limestone)

Crinoidal Limestone (comprising Calcite/Aragonite CaCO3)

Fossilized Coral

Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)

Chert (specifically Flint or Jasper variant)

Microcrystalline quartz (SiO2)

Shale with Coprolite influence

Argillaceous sedimentary rock (Shale/Mudstone)