Sedimentary Rocks

• Carbonatic Rocks
• Evaporite rocks
• Terrigenous Rocks
Grain Size
Terrigenous Rocks
Packing
Roundness
Sorting

• Weathering

Turbidite

• Turbidites

Fossils

• Ammonites
• Bivalves
• Brachiopods
• Gastropods
• Trilobites

Sedimentary Minerals

• Anhydrite
• Baryte
• Chalcedony
• Gypsum
• Glauconite
• Magnesite

Texture

• Allochem
• Carbonatic Matrix
• Dolomitization
• Syntaxial Overgrowthn

Rocks

• Ammonitico Rosso
• Arkosic Sandstones
• Bioclastic Grainstone
• Oolitic Ironstone
• Breccia
• Conglomerate
• Encrinite
• Lithic Arenite
• Mudstone
• Oolite
• Orthoconglomerate
• Radiolarite
• Wackestone

Chalcedony - SiO₂

Chalcedony is not scientifically its own mineral species, but rather a form of Quartz in microcrystalline form. The name chalcedony comes from the Latin chalcedonius (alternatively spelled calchedonius). The name appears first in Pliny the Elder's Naturalis Historia as a term for a translucid kind of Jaspis. Chalcedony is quite varied in its formation habits. It sometimes occurs in geodes, lining the cavity with mammilary blobs. Its Agate variety is also found in geodes, commonly lining the outer layer underneath the larger Quartz crystals. Chalcedony also forms pseudomorphs after organic material.

Bibliography

• Deer, W.A., Howie, R.A., Zussman, J. (1998) Rock-forming Minerals.
• Optical Mineralogy : The Nonopaque Minerals by Phillips / Griffen
• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc

Photo

Chalcedony veins in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Chalcedony veins in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Chalcedony veins in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)
cavity-filling Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Chalcedony vein in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Chalcedony vein in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)
cavity-filling Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Chalcedony veins in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)
Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)
Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)
Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)	Fibrous Chalcedony crystals in a Siliceous rock (chert). XPL image, 20x (Field of view = 1mm)
		Chalcedony vein in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)
cavity-filling Chalcedony crystals in a Siliceous rock (chert). XPL image, 2x (Field of view = 7mm)	cavity-filling Chalcedony crystals in a Siliceous rock (chert). XPL image, 10x (Field of view = 2mm)