Mineraloid Like Synthetic Material

Chert (Yellow or Brown Jasper)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (SiO2 based with quartz, feldspar, or lithic fragments)

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Ferruginous Sandstone

Ferruginous Clastic Sedimentary Rock

Chert (Nodular)

Cryptocrystalline Quartz (SiO2)

Muscovite Mica (Granitic Pegmatite)

Muscovite - KAl2(AlSi3O10)(OH)2

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Red Mudstone (Siltstone)

Lutite (primarily Quartz and Clay minerals with Hematite)

Chert (varieties include Flint and Mudstone)

Microcrystalline Silica (SiO2)

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline silicon dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ferruginous Quartzite (Red Sandstone/Quartzite)

Quartzite with Iron inclusions (SiO2 + Fe2O3)

Sandstone

Arenite (primarily SiO2)

Larimar

Pectolite [NaCa2Si3O8(OH)] with copper substitution

Schist

Mica Schist (predominantly Muscovite/Biotite)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Pink Rhodonite

Manganese Silicate (MnSiO3)

Chert (specifically Flint)

Cryptocrystalline Quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

Sandstone Pebble

Arenite (primarily Quartz, SiO2)

Chert (Arrowhead)

Chert (primarily Microcrystalline Silica, SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (primarily SiO2)

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Sandstone (Pebble)

Arenite (primarily SiO2)

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite

Quartz (Raw Chunk)

Silicon Dioxide (SiO2)

Biotite Schist

Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)

Chert (Cherty Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Engineer Quartz/Quartzite

SiO2 (Silicon Dioxide with binders)

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(F,OH)2

Chert (specifically Flint or Common Opal)

Silicon Dioxide (SiO2)

Red Jasper (Quartz)

Silicon Dioxide (SiO2) with Iron impurities

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

Chert (variations include Chalcedony and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Arrowhead/Tool variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite

Iron Sulfide (FeS2)

Feldspar Granodiorite

Granodiorite (Na,Ca)(Si,Al)4O8

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)