Hardness Testing Pencils - TT52

This deluxe set provides a range of hardness pencils from 2-9 on the Moh's scale for testing the hardness of gemstones and menerals, two hardness plates of 3.5 and 5.5 and a polishing stone to keep the pencils sharp and in good condition. The luxury wooden case also includes a magnet and a streak plate for further testing.

note.

Hardness testing can be destructive.