Drusy (druzy) gems come more and more popular in jewelry due to it stunning color game given them the nature. Rainbow or iridescent pyrite was found in Russia in the bank of the Russian biggest river called Volga. Deposits locate close to the city of Ulyanovsk, in the field of coastal landslides. Waters of the river eroding the ancient clays of high steep bank of the river and washing away septarias from a coast. Rocks then roll down on the river bottom and clay go-away downsteam.
This kind of pyrite druzy located inside of round shape clay nodule - called Septaria.
Fine layer of microcrystals coating a surface of matrix consisting of clay and calcium mixture - Siderite.Geological origin septarias have sizes about to 1 - 8 inches in diameter. The shades of color cover all rainbow range from red, orange, yellow, green to deep blue, purple and violet ("peacock" variety color). Clay nodules are the most diverse forms.
Note: words, photos and pictures on this web site are sensitive to click. Native gold pyrite and pyrite covered oxide film gave a very much magic optical effect of rainbow shining. It happens due to light interference in thin films. http://en.wikipedia.org/wiki/Light_interference
Rainbow pyrite is relatively new material in Russia.
Very interesting specimen of iridescent pyrite with sphalerite you can see on youtube from Teresa Rocks collection. <-- click here
Specimen calcite & iridescent pyrite balls from Mexica <-- click here
Specimen from China <-- click here
Specimen from Slovakia <-- click here
Would like to see native pyrite from Volga Russia? <-- Click here.
Pyrite as marcasite jewelry, semiconductor, solar energy, solar cells, cat's whisker detector and more, go to http://en.wikipedia.org/wiki/Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold. The color has also led to the nicknames brass, brazzle and Brazil, primarily used to refer to pyrite found in coal.
More about druse ( druzy, drusy) see here http://en.wikipedia.org/wiki/Druse_(geology)
In geological usage druse (drusy,druzy) is an incrustation of small crystals on a rock fracture surface, or mineral.
More about pyrite? Click here <-
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