Hardness and Toughness standards of gemstones
Gemstones require different cleaning methods based on their hardness and toughness. The measure of a mineral’s hardness and it’s resistance to scratching was invented by a mineralogist named Friedrich Moh. He invented a scale that ranges from talc (number 1) being the softest, to diamonds (number 10) being the hardest substance. The toughness of a gemstone is the resistance to breakage. The combination of the toughness and hardness of a gemstone largely defines its durability.
To clean Howlite:
Howlite’s toughness is fair and on Moh’s hardness scale it receives a 3-3 ½ . This means that steaming your howlite can be risky and shouldn’t be done. It is also not the best idea to boil them. The safest way to clean your howlite is to use soap or an untreated cloth.
