8dbffb94ef30436199505054e9a3038f
it’s recommended in BiS gear but Unstable Topaz
and other unstable gems are linked to The raid on Bash’ir Landing.
Aether-tech Adept - NPC - TBC Classic (wowhead.com) here’s the comment on wowhead suggesting this and here’s the list of gems (look for unstable Burning Crusade Classic Gems - Guides - Wowhead
It appears to be linked to a vendor that appears in raid event in BEM and starts at Ogrila so my guess is it is linked to P2 or later but not P1.