(10-21-2015, 01:17 PM)Unnamed Mercenary Wrote: The Black Mage Soul Crystal is literally called the Gem of Shattoto. By Shattoto, the person who one could argue "invented" Black Magic because she couldn't be a Thaumaturge. It's basically her "here's how I did this" memory in a rock. Could someone else rediscover her methods? Maybekinda. The 3.0 scenes seem to imply that people tried and got burned for it.
The thing is that the Gem of Shattoto is a very specific item. Whether or not there are other BLM soulstones is not touched upon.
Depending on how you interpret the lore that we have, it's likely that there are others, because you can't have a Wizarding War without multiple Wizards, but your mileage may vary.