China gemstone’s Physical properties

The mechanical properties of precious stones

1, the hardness
Hardness - that precious ability to resist external mechanical action. The relative hardness and hardness is divided into absolute hardness. Using the relative hardness of hardness The scheme, which consists of 10 kinds of common minerals. 10 small to large order of hardness: ① talc; ② gypsum; ③ Calcite; ④ fluorite; ⑤ apatite; ⑥ feldspar; ⑦ quartz; ⑧ topaz; ⑨ corundum; ⑩ diamond. Test method is used to characterize these minerals precious stones engraved with marks obtained, the precious stones jewelry supplier than the hard minerals such as gold topaz emerald can be carved, and engraved fixed corundum, its relative hardness of about 8.5. In addition to standard hardness minerals, but also commonly used to determine the hardness of other simple tools, such as nail hardness of about 2.0 to 2.5, copper 3.0 key, small blades, 5.0 to 5.5, glass is 6.0. Note that it should not have been refined with good carved stones to avoid damage gem. Absolute hardness is measured using microhardness data, but not commonly used in practice.
In addition to equiaxed crystalline and amorphous gem, the other most of the stones as the nature of anisotropy in different crystal directions with different hardness, the most obvious is kyanite, parallel to the cylinder on the crystal surface hardness 4.5, the direction of the vertical cylinder hardness of 6.5.
Use of differential hardness of china gemstone wholesaler is a very effective method.
2, cleavage, fracture, crack reason
Cleavage - is the sapphire crystal in the external force against time, a certain degree of crystal orientation along the crack of the nature of the crack in the formation of the cleavage plane is face to face. Mineralogy will be produced by cleavage were divided into five easy to difficult, that is very complete, full, medium, not completely, absolutely incomplete. Such as muscovite with a very complete set of cleavage, along its direction can peel into very thin sheets of muscovite; Rhodonite with complete cleavage, while garnet, quartz, tourmaline and other reasons are puzzling. Cleavage can be identified using some gems, but cleavage is restricted gem quality and processing of adverse factors.
Fracture - refers to any fracture after being hit by the china gemstone supplie to open the section, often uneven or rugged. Difficult to produce cleavage of the sapphire crystal will be easy to produce fracture. Such as Quartz (Crystal) produces easy hit conchoidal fracture.
Crack reason - that some students with twin gems even after being hit by the power split along the twin nature of joints, such as moonstones often along the lattice inside the double twin crystal plane crack reasons appear.
3, ductile and brittle
The ability to resist external damage gem stones, said the resilience, toughness little gem is brittleness. Toughness (resistance) and the hardness ratio does not necessarily have a fixed relationship, such as the hardness of diamonds, the largest, but its toughness is small, about 7.5, so although it is hard wear, but are easily broken when hit. A lot of stones are more brittle, or worn in the processing time required to be taken to avoid ground impact and falling. On the contrary, the toughness of jade is very high.