Archivos de Etiquetas: Baolong shares: la dureza y densidad de las gemas

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The ability of a gemstone to resist pressing, El rayado o pulido se llama dureza.. The hardness of a gemstone is related to its chemical composition, chemical bond and crystal structure. Hardness is one of the three essential elements of gemstones, and it is also a problem that must be paid attention to in gemstone […]