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

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Ironstone (Limonite/Hematite)

Ferruginous sedimentary rock (Fe2O3·nH2O / Fe2O3)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Chalcedony (Botryoidal/Drusy Quartz)

Silicon Dioxide (SiO₂)

Pink Granite

Granite (Felsic plutonic rock)

Fossilized Shark Tooth (Otodus obliquus)

Otodus obliquus (composed primarily of Fluorapatite)

Amazonite

Microcline (KAlSi3O8 with lead impurities)

Slickenside in Limestone

Tectonized Limestone / Calcite (CaCO3)

Blue Lace Agate (often dyed)

Silicon dioxide (SiO2) - variety of chalcedony

Quartz (Specifically Clear to Smoky Quartz point)

Silicon Dioxide (SiO2)

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Siltstone with flute casts or scratch marks

Clastic Sedimentary Rock (Siltstone/Fine-grained Sandstone)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Chert (Commonly known as Flint)

Microcrystalline Quartz (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Chert / Flint

Chert (Microcrystalline Quartz, SiO2)

Lapis Lazuli

Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Septarian Nodule Segment (Commonly known as Dragon Stone or Lightning Stone)

Septarian Nodule (CaCO3 / Hydrated Calcium Carbonate)

Sandstone (with garnet granules)

Clastic sedimentary rock (primarily SiO2 with Fe3Al2(SiO4)3 inclusions)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Amber with inclusion

Amber (Fossilized Tree Resin)

Brown Chert

Cryptocrystalline Silica (SiO2)

Siderite Concretion

Ironstone (Siderite) Concretion, FeCO3

Diorite (River Pebble)

Intermediate plutonic igneous rock

Limestone

Calcium Carbonate (CaCO3)

Quartz (specifically Milky/Gray Quartz vein)

Silicon Dioxide (SiO2)

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

Sand Dollar Fossil (Echinoidea)

Class Echinoidea (likely order Clypeasteroida), CaCO3 (Calcite)

Yellow Howlite (Dyed Magnesite/Howlite)

Dyed Ca2B5SiO9(OH)5 (Howlite) or MgCO3 (Magnesite)

Jasper in Basalt Matrix

Silicon Dioxide (SiO2) with impurities; Chalcedony

Red Moss Agate (Jasper)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Limestone

Calcium Carbonate (CaCO3)

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Dyed Agate (Tumbled)

Silicon Dioxide (SiO2) - stained microcrystalline quartz

Agate Nodule (partially vuggy Quartz)

Silicon Dioxide (SiO2)

Quartz Pebble (Milky and Gray)

Quartz (Silicon Dioxide, SiO2)

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Coral Fossil (Favosites type)

Phylum Cnidaria, Class Anthozoa (often CaCO3 - Calcium Carbonate)