Rock Identifier

Category

Organic Gemstone (Often Associated With Sedimentary Sequences)

Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.

Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Chert (Nodule) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (specifically a Chert Nodule or Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a Chert Nodule or Flint)

Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Ironstone variety) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Chert (Jasper/Ironstone variety)

Silicon Dioxide (SiO2) with iron oxide inclusions

Map Jasper (Grey Picasso Jasper) (Silicon Dioxide (SiO2) with impurities) — sedimentary

Map Jasper (Grey Picasso Jasper)

Silicon Dioxide (SiO2) with impurities

Pyrite (Pyrite (Iron sulfide, FeS₂)) — mineral

Pyrite

Pyrite (Iron sulfide, FeS₂)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (with Limestone and Iron Oxide staining) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image) (Quartz (SiO₂ - Silicon Dioxide)) — Mineral

Quartz (likely a macrocrystalline variety like milky quartz or smoky quartz, given the appearance in the image)

Quartz (SiO₂ - Silicon Dioxide)

Gneiss (with Quartz and Mica) (Gneiss) — metamorphic

Gneiss (with Quartz and Mica)

Gneiss

Aquamarine (Beryl (Be3Al2Si6O18)) — mineral

Aquamarine

Beryl (Be3Al2Si6O18)

Chert (containing small fossils) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (containing small fossils)

Chert (Microcrystalline Quartz, SiO2)

Common Opal (Hydrated silica (SiO2 " nH2O)) — mineral

Common Opal

Hydrated silica (SiO2 " nH2O)

Native Sulfur (Sulfur (S)) — mineral

Native Sulfur

Sulfur (S)

Gneiss (High-grade metamorphic rock (Gneiss)) — metamorphic

Gneiss

High-grade metamorphic rock (Gneiss)

Chert (Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper/Agatized Chert) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper/Agatized Chert)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

Red Jasper (Silicon Dioxide (SiO2) - Opaque microcrystalline quartz) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) - Opaque microcrystalline quartz

Jasper (Green Jasper / Bloodstone variant base) (Silicon Dioxide (SiO2) with impurities of chlorite and iron oxides) — sedimentary

Jasper (Green Jasper / Bloodstone variant base)

Silicon Dioxide (SiO2) with impurities of chlorite and iron oxides

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (with Lichen) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Lichen)

Microcrystalline Quartz (SiO2)

Jasper (Cryptocrystalline Quartz (SiO2)) — sedimentary

Jasper

Cryptocrystalline Quartz (SiO2)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint (Chert (SiO2)) — sedimentary

Chert / Flint

Chert (SiO2)

Limonite after Pyrite (Prophecy Stone or Ironstone Concretion) (Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)) — mineral

Limonite after Pyrite (Prophecy Stone or Ironstone Concretion)

Goethite/Limonite pseudomorph after Pyrite/Marcasite (FeO(OH)·nH2O)

Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (Flint Nodules) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint Nodules)

Microcrystalline Quartz (SiO2)

Shale or Siltstone (Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)) — sedimentary

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)

Chert / Jasper / Agate (Chalcedony Group) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Chert (Tan/Grey) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Tan/Grey)

Chert (Silicon Dioxide, SiO2)

Chert (Iron-stained) (Chert / Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Iron-stained)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Chert (often referred to as Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often referred to as Flint)

Chert (Microcrystalline Quartz, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (Nodule) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (and Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper) (Silicon dioxide (SiO2)) — sedimentary

Chert (Jasper)

Silicon dioxide (SiO2)

Petrified Dinosaur Bone (Gembone) (Agatized Dinosaur Bone) — sedimentary

Petrified Dinosaur Bone (Gembone)

Agatized Dinosaur Bone

Chert Nodule (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)