142-146In stock
5 variants
Testing stone
Black bar from close-grain siliceous shale. Used to determine assay (metal purity test).
from
€14
Category 10In stock
Testing stone
A siliceous shale testing stone (touchstone) for metal purity testing and assay work, used to streak-test gold, silver and other precious metal alloys. Five sizes, from 40×60mm to 120×140mm, for benches ranging from a single jeweller's station to a busier assay workflow.
Material
Siliceous shale
Temperature
Lab use
Application
Metal purity testing and assay.
Frequently asked questions
What is a testing stone used for?
Metal purity testing and assay — streak-testing gold, silver and other precious metal alloys against the stone.
What is the stone made from?
Siliceous shale, the traditional material for touchstone assay testing.
What sizes are available?
Five sizes, from 40×60mm to 120×140mm.