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

Grey Quartzite Pebble

Quartzite (primarily SiO2 - Silicon Dioxide)

Amethyst

Amethyst (SiO2 with Iron impurities)

Fossiliferous Limestone (Shell Fragment)

Biogenic Limestone (Calcium Carbonate / CaCO3)

Fluorite (Purple variety)

Calcium Fluoride (CaF2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Jasper-Quartz Conglomerate / Chert

Siliceous Sedimentary Rock (SiO2)

Amethyst/Smoky Quartz Cluster

Silicon Dioxide (SiO2)

Marble

Recrystallized Calcite (CaCO3)

Optical Calcite

Calcium Carbonate (CaCO3)

Chert / Quartz Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Geode with Quartz and Chalcedony

Silicon Dioxide (SiO2)

Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Banded Chert with Quartz Veining

Microcrystalline Quartz (SiO2)

Chert (Common Opal/Agate mixture)

Microcrystalline Quartz (SiO2)

Amethyst (Quartz)

Amethyst (SiO2 with iron impurities)

Chevron Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Marble

Recrystallized Calcite (CaCO3)

Lapis Lazuli

Lazurite-rich metamorphic rock; (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Lapis Lazuli

Lapis Lazuli (Complex aggregate of Lazurite, Calcite, and Pyrite)

Lapis Lazuli

Lapis Lazuli (Rock containing Lazurite, Calcite, and Pyrite)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Druzy Quartz (on Chalcedony/Agate base)

Silicon Dioxide (SiO2)

Amethyst (Druzy Cluster)

Amethyst (Silicon Dioxide with Iron impurities), SiO2

Limestone

Calcareous sedimentary rock (CaCO3)

Chalcedony (Agate/Quartz)

Silicon Dioxide (SiO2)

Quartz (specifically Citrine or Yellow Quartz)

Silicon Dioxide (SiO2)

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Amethyst with Marcasite accents

Amethyst (Silicon Dioxide SiO2) and Marcasite (Iron Sulfide FeS2)

Lapis Lazuli

Lapis Lazuli (Complex aggregate mainly of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Limestone

Sedimentary rock composed of Calcium Carbonate (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)

Blue Calcite

Calcium Carbonate (CaCO3)

Charoite

K(Ca,Na)2Si4O10(OH,F)·H2O

Quartz (likely Milky Quartz)

Quartz (SiO₂ - Silicon Dioxide)

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

Geode (Quartz)

Silicon Dioxide (SiO2)

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Lapis Lazuli

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2

Stichtite (often found in Serpentinite)

Stichtite Mg6Cr2CO3(OH)16·4H2O

Chevron Amethyst

Quartz (SiO2) with patterned Amethyst and White Quartz/Milky Quartz