宝石的力学性质(国外英文资料).docVIP

宝石的力学性质(国外英文资料) Proportion (relative density) : The weight of the stones and the weight of the parts water (4 ℃) than for the specific gravity value of precious stones. Gravity is an important parameter to identify gems (especially jade). The value of a gem is controlled by its chemical composition and crystal structure. As a result, the proportion of each gem has its fixed values, but due to the mass with elephant, the influence of impurity inclusions, the proportion of the measured value will have a small range. 2, hardness: The performance of resistance pressure, etching, or grinding is called the hardness of a gem. The most significant of the gems is relative hardness. Often used is the mohs hardness, which consists of ten minerals, which are formed from soft to ten. ? Its level only indicates the relative size of the hardness, not the absolute hardness, and the difference in hardness between all levels is not equal. ? 3, toughness: Refers to the ability of a gem to resist tearing and tearing apart, the ability to resist division. A high degree of toughness indicates that the gem is difficult to break, and the relationship between toughness and hardness is not positively correlated, and the firmness is related to the structure of the stone. Example: a diamond with a hardness of 10 is developed with octahedral cleavage, and its firmness is less than the soft jade of 6-6.5, whereas the firmness of soft jade comes from its fibrous structure. ? ? Cleavage and fracture: Cleavage: the crystal cracks in a certain crystalline direction to the smooth surface. Fracture: the gem is acted by the external force to send random random, irregular rupture surface. Cleavage not only makes sense of the gem, but also has a great effect on the processing of the gem. ? 1, the hardness Hardness -- the ability of a gem to resist foreign mechanical action. Hardness is relative hardness and absolute hardness. It is composed of ten common minerals. The scale of ten degrees of hardness fr