Mineraloid (Organic)

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)

Quartzite

Quartzite (primarily SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Banded Iron Formation (Hematite/Magnetite-rich)

Banded Iron Formation (BIF)

Almandine Garnet in Matrix

Almandine, Fe3Al2(SiO4)3

Granite

Granite (Felsic Plutonic Rock)

Rough Green Calcite

Calcite (Calcium Carbonate, CaCO3)

Chert (variations include Flint or Jasper)

Chert (SiO2)

Chert (variations include Flint/Jasper)

Chert (Silicon Dioxide, SiO2)

Chert (Flint variety)

Chert (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Mica Schist with Quartz

Mica-Quartz Schist (Muscovite subclass)

Blue Calcite

Calcite (CaCO3)

Chert (Flint variety)

Chert (SiO2)

Chert (and associated Sedimentary rocks)

Microcrystalline Silica (SiO2)

Mica Schist

Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Mookaite Jasper

Mookaite (variety of Chert/Jasper), Silicon Dioxide - SiO2

Chert (Field-collected Arrowhead-shaped Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite

Quartzite (SiO2)

Chert (often called Flint when dark)

Microcrystalline silicon dioxide (SiO2)

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Garnet Schist

Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)

Chert (Flint variety)

Silicon Dioxide (SiO2)

Banded Chert

Cryptocrystalline Quartz (SiO2)

Banded Chert (River Cobble)

Microcrystalline Quartz (SiO2)

Greenstone

Chlorite schist / Meta-basalt

Quartzite

Quartzite (primarily SiO2)

Banded Iron Formation (Jaspilite)

Banded Iron Formation (BIF); predominantly Hematite (Fe2O3) and Magnetite (Fe3O4) with Chert/Jasper (SiO2)

Chert Pebble

Microcrystalline silica (SiO2)

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Chert (variations include Flint or Jasper)

Chert (Silicon Dioxide, SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (Yellow or Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Unakite

Unakite (Metasomatized Granite)

Chert (Arrowhead/Tool Grade)

Microcrystalline Quartz (SiO2)