Aquamarine has good hardness 7 . 5 to 8 on the mohs scale and a wonderful shine 良好的硬度在摩氏硬度表中是被列为
2.
The sapphire belongs to the corundum group , the members of which are characterised by their excellent hardness 9 on the mohs scale 我们一会就会详解。蓝宝石是属于刚玉家族，在摩氏硬度表中刚玉的硬度是被列为
3.
This gemstone has excellent wearing qualities and is easy to look after , for all tourmalines have a good hardness of 7 to 7 . 5 on the mohs scale 碧玺是很适合制成珠宝来佩带，且易照顾，因为它有著良好的硬度，在摩氏硬度表中为
4.
From a chemical - mineralogical point of view , emeralds are beryllium - aluminium - silicates with a good hardness of 7 . 5 to 8 , and belong , like the light blue 从化学矿物学角度来看，祖母绿是铍铝的硅酸盐矿物，有良好的硬度，在摩氏硬度表中为
5.
Ruby is the red variety of the mineral corundum , one of the hardest minerals on earth , of which the sapphire is also a variety 红宝石的矿物名称为刚玉，其硬度是地球上硬度最佳的矿物之一，而蓝宝石也属刚玉家族。在摩氏硬度表中刚玉的硬度是被列为
6.
Once the tourmaline has survived the tough cutting process , it is , with its good hardness 7 to 7 . 5 on the mohs scale , a relatively robust gemstone which is easy to look after 一旦成功地通过切割程序，碧玺是极为强健的宝石，有着良好的硬度，在摩氏硬度表中为
