Howlite
Howlite (Calcium borosilicate hydroxide: Ca2B5SiO9(OH)5)
Category
Browse sedimentary (chemically precipitated) specimens identified by the Rock Identifier community.
Howlite
Howlite (Calcium borosilicate hydroxide: Ca2B5SiO9(OH)5)
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
Chert (Flint Nodule)
Silicon Dioxide (SiO2)
Yellow Jasper with Red Inclusion
Silicon Dioxide (SiO2) with Iron Oxides
Brown Agate
Cryptocrystalline Silica (SiO2)
Jasper (Red and Tan Jasper)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert Nodules in Limestone
Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Chert (Jasper/Agate variant)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
Quartz Geode
Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Cryptocrystalline Quartz (SiO2)
Chert (often colloquially called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Calcite
Calcite (CaCO₃)
Calcite crystal
Calcite (CaCO₃)
Quartz (Water-worn Pebbles)
Silicon Dioxide (SiO2)
Chert (Nodule / Geode fragment)
Microcrystalline Quartz (SiO2)
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Fancy Jasper (Agate/Chert mix)
Silicon Dioxide (SiO2) with various inclusions
Limestone
Calcium Carbonate (CaCO3)
Quartz Vein in Host Rock
Silicon dioxide (SiO2) veining in silicate matrix
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert River Pebble
Microcrystalline Quartz (SiO2)
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Milky Quartz / Quartz Geode Fragment
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)