rystal structure

A brief overview of amphibole
Amphiboles group in crystal structure with double chain structure, hydroxyl containing magnesium, iron, calcium, sodium, aluminum silicate ( with [si4o11] 6 - partial silicate. ). According to the different crystalline attribution, divided into anthophyllite, monoclinic amphibole and three amphibole three subgroup. Anthophyllite subtribes are anthophyllite and gedrite ( gedrite ); monoclinic amphibole sub-clan mainly tremolite,pearl jewelryactinolite, hornblende amphibole ( common hornblende ), blue ( glaucophane ), arfvedsonite ( arfvedsonite ) and so on; three amphibole subgroup of three oblique amphibole ( enigmatite ) and rhoenite ( rhoenite ) etc.. These amphibole while chemical composition and crystal system is not the same, but have many similar properties.
The crystal is a long column, acicular or fibrous; crystal cross-sectional from diamond to hexagonal; aggregate as granular, fascicular and radial. Hardness is 5 ~ 6, rhombohedral cleavage parallel column {110} medium, the two groups into 56o or 124o cleavage. Relative density ranged from 3 to 3.5. General glass gloss. Transparent and opaque. The color varies because of the variety and impurity. Light with breed change slightly to have the difference, therefore, is used for identification of different varieties of main mark. Amphibole group minerals is one of important rock forming minerals. The hornblende is widely distributed in neutral and acidic igneous rocks, but also many rocks consisting mainly of minerals.
Tremolite actinolite, is an important product of contact metasomatic metamorphism. Na-rich alkali amphibole is alkaline rock consisting mainly of minerals,plastic bag manufacturer in many of these amphibole group mineral, known to have a gem value mainly tremolite actinolite, and formed the nephrite. There is a deep black hornblende crystals are also expected to become a potential source of black gem. In industry, people uses basically is a fibrous amphibole, the so-called amphibole asbestos.
The gold content of 75% white gold is known as white 18 K gold, commonly known as" K white gold", which contains copper, silver and other metals, and platinum is two concepts. Golden yellow gold, white gold, red, gold and other varieties, 18K gold jewelry gold content of not less than 750 per thousand, can be marked as 18K or G18K, G750, Au750, 18K gold 750, gold; gold jewelry gold content of not less than 990 per thousand, can be marked as gold or G990, Au990, gold 990; thousands of gold jewelry gold content of not less than 999 per thousand, can be marked as thousands of gold or G999, Au999, gold 999. In addition the market ( especially in foreign countries) can also be seen some 9K ( gold content of not less than 375 per thousand), 14K ( gold content of not less than 585 per thousand) and 22K ( gold content of not less than 916 per thousand) and gold jewelry.
For platinum jewelry, which have Pt signs, without this flag, certainly not platinum jewelry. Common platinum jewelry has Pt900, Pt950 and Pt990. Palladium jewelry is Pd at the beginning, the precious metal is nearly two years before being individually for the production of jewelry,office furniture currently on the market popular palladium jewelry mainly Pd950 and Pd990.
Common market, silver jewelry 925 silver, who is also known as the sterling silver, silver content requirements shall not be less than 925 per thousand, 75 other % can be copper or antioxidant elements, can be marked as S925 or Ag925, Silver 925; plus a fine silver, requirements of silver content shall not be less than 990 per thousand, can be marked as S990 or Ag990, 990 silver. Occasionally see 800 Silver ( silver content shall not be less than 800 per thousand).