Thank you to all who participated in my guessing contest over the past week!
The winner is...Franchesca!
Black spinel was the answer to this mystery stone, and I took down anyone who said any sort of spinel as their answer. Randomizer selected the number that corresponded to her comment.
Franchesca, please email me so we can discuss your black spinel earrings! :) stardust at aliciadabney dot com
I will post a photo of the earrings once they have been created.