Sedimentary (Chemically Precipitated) Or Metamorphic

Biotite Schist with Garnet

Garnet-Biotite Schist

Hematite Beads

Hematite (Fe2O3)

Banded Agate (specifically Carnelian Agate slice)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Fuchsite Schist

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Schist

Mica Schist

Agate (Common Chalcedony)

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Howlite (Dyed to resemble Turquoise)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Astrophyllite

Astrophyllite (K2NaFe7Ti2Si8O26(OH)4F)

Quartz Pebble

Silicon Dioxide (SiO2)

Azurite-Malachite with Limonite

Cu3(CO3)2(OH)2 (Azurite) / Cu2CO3(OH)2 (Malachite)

Limestone

Calcium Carbonate (CaCO3)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite Beach Pebble

Quartzite (primarily SiO2)

Kyanite (Blue or Blue-Grey)

Kyanite (Al2SiO5)

Garnet (likely Almandine, Pyrope, or a blend)

Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)

Chert (specifically Jasper or Flint type)

Microcrystalline Quartz (SiO2)

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Chert (SiO2)

Chert Nodule (Commonly known as Flint or River Rock)

Silicon Dioxide (SiO2)

Chert (Flint Nodular)

Chert (Silicon dioxide, SiO2)

Mica Schist

Mica Schist (primarily Muscovite and Biotite composition)

Ruby in Zoisite

Anyolite (Ruby in Zoisite)

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite mica

Amber

Succinicum (C10H16O)

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Limestone

Calcium Carbonate (CaCO3)

Shungite

Non-crystalline carbon (high-carbon metamorphic rock)

Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Gneiss (Metamorphic Rock)

Gneiss

Schist/Phyllite

Metamorphic Schist (Chlorite Schist variety)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (varietal: Flint/River Pebble)

Cryptocrystalline Quartz (SiO2)

Chert (Cherty Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)