Saturday, August 09, 2008

Brass = Cu3Zn2, Copper zinc , color Yellow,

Brass is naturally occurring crystals of a copper nickel alloy with a formula similar to what we know as brass. These specimens are also not common, but are extremely rare and have only been found in a couple of localities. Brass could be considered an official mineral if the naturally occurring crystals prove to have a unique structure and chemistry from other copper nickel alloys. That may prove difficult or impossible and if so, brass will then be discounted as a mineral.

Brass is classified as an element dispite the fact, that in chemical reality, it is a compound. Minerals like brass are alloys with metallic bonds that are very similar to the more pure metallic elements and are thus classified as elements.

PHYSICAL CHARACTERISTICS:

    * Color is yellow to brassy yellow.
    * Luster is metallic.
    * Transparency: Specimens are opaque.
    * Crystal System is isometric.
    * Crystal Habits are limited to tiny grains.
    * Cleavage is absent.
    * Specific Gravity is 8.4 - 8.7 (man-made brass)
    * Streak is brassy brown.
    * Notable Occurrences are limited to two localities in Siberia, Russia; Tolbachik Volcano, Kamchatka and Vol'sk-Vym Ridge, Middle Timan.
    * Best Field Indicator is color, locality, density and rarity.

Chemical Formula: Cu3Zn2
Composition: Molecular Weight = 321.42 gm
   Zinc    40.69 %  Zn
   Copper  59.31 %  Cu
          ______ 
          100.00 % 
Empirical Formula: Cu3Zn2
IMA Status: Not Approved IMA


Synonym: Laiton
  Messing

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