Man Made Material (Constructed)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Blue Topaz (facetted in jewelry)

Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)

Milky Quartz (or Bull Quartz)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide) - SiO2

Chert (Flint/Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chalk / Sedimentary Limestone

Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock

Chert / Flint Nodules in Sandstone

Microcrystalline Quartz (SiO2) within Clastic Sedimentary Rock

Milky Quartz (Tumbled Pebble)

Silicon Dioxide (SiO2)

Chert (variant Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Chert (varieties include Flint and Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper/Flint)

Chert (SiO2)

Rough Diamond

Diamond (pure Carbon, C)

Assorted Semi-Precious Gemstone Crosses

Quartz, Silicates, Carbonates (various)

Grey Slate

Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Gneiss (with Quartz Vein)

Gneiss (Metamorphic rock of varying mineralogy)

Chert (often called Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Silty Sand / Loam

Unconsolidated Clastic Sediment (Silicon Dioxide / Alumino-silicates mixture)

Granodiorite (Gneissic texture)

Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)

Quartz

Silicon Dioxide (SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Milky Quartz

Silicon Dioxide (SiO2)

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Lapis Lazuli

Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)

Chert / Flint (with Iron Staining)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Serpentine

Serpentinite (rock) containing serpentine minerals (e.g., Antigorite, Lizardite, Chrysotile)

Herkimer Diamond

Quartz (SiO2)

Nuummite

Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)