I prospect for sapphires, do crystal clear sapphires exist?

Question

it is not quartz, weights in at a little under 6kts.

Answer 1

Yes, colorless sapphires exist! To tell sapphire (corundum) apart from quartz or another type of gemstone, you can make some simple observations:

Hardness - Attempt to scratch it with a piece of quartz. If it does not, you have a crystal that is harder than quartz. Your blade isn't going to work because the hardness of steel usually ranges from 5-7. Sapphire is 9.

Crystal features - Note the type of crystal habit that the stone comes in. Sapphires usually grow as hexagonal bipyramids. Quartz usually comes in a rhombohedral habit.

Specific Gravity - This is probably the best test to do if you have no access to gemological equipment. You can build your own hydrostatic scale (google it!) and then calculate the SG of your rock by finding the ratio between the weight of the gem in air vs in water. The SG of corundum is 3.9-4. Quartz is lower at 2.56.

Hope that helps!

Answer 2

Yes. A common application for sapphires is in optics because of thermal resistance and mechanical strength. From what I understand, they are increasingly being used in braces for teeth. As Ed said, sapphires are part of the corundum family which have many useful applications.

If I were you, I'd take the stone to the geology department of your local university to determine what it is. Finding the density hardness and chemical composition is the best way to figure out what you have as colour varies a lot amongst gemstones.

Answer 3

Yes colorless sapphires do exist, as do other unusual colors...they are all corundum. Red ones are called rubies by convention. It's the chemical composition that determines the species. Find out it's density and hardness.