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

Pyrite in Matrix (likely Quartz or Schist matrix)

Iron Sulfide (FeS2)

Granite

Phaneritic Plutonic Felsic Rock

Chert (containing small fossils)

Chert (Microcrystalline Quartz, SiO2)

Fossilized Shark Tooth in Matrix

Otodus sp. (likely Otodus obliquus)

Chert Pebble (with Quartz Vein)

Chert (Cryptocrystalline Silica - SiO2)

Blue Lace Agate

Silicon Dioxide (SiO₂), a variety of Chalcedony

Limestone

Calcium Carbonate (CaCO3)

Chert (specifically Green Chert/Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chalcedony (Quartz Nodule)

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Biotite Gneiss

Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Coquina (Fossiliferous Limestone)

Coquina (Organic Clastic Limestone)

Rose Quartz

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartzite River Rock

Metamorphic Quartzite (primarily SiO2)

Chert (River Pebble)

Chert (Silicon Dioxide, SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Sandstone (with Iron Staining)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Basalt

Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)

Limestone

Calcium Carbonate (CaCO3)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Blue Dyed Agate

Silicon Dioxide (SiO2)

Basalt (River or Beach Pebble)

Basalt (Mafic Extrusive Igneous Rock)

Dyed Alum or Dyed Quartz (Ornamental Crystal)

Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]

Chert (often called Jasper or River Rock)

Chert (SiO2)

Agate (Carnelian-Blue Agate mix)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

Horn Coral Fossil

Rugosa (extinct order of solitary corals)

Amazonite

K(AlSi3O8) - Lead-bearing Microcline (Potassium Feldspar)

Quartz (specifically Quartzite or Massive Quartz)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Banded Chert

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartz River Pebble

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)