Zhangzhou Sino Science & Technology Co., Ltd. [China]

Hardness pencil is a good tool for gemstones.it is used to test the gemstone's hardness.

Product Name: Hardness Pencil

The scale in increasing order of resistance to abrasion

1.  TALE

2.  GYPSUM

3.  CALCITE

4.  FLUORITE

5.  APATITE

6.  ORTHOCLASE

7.  QUARTZ

8.  TOPAZ

9.  CORUNDUM

10. DIAMOND

Hardness Pencil jewelly instruments