Huge stone necklace MUST SEE a sterling DETAILED. HUGE ! HUGE ! HUGE !

If anyone may know what stone this is please tell me. I do appreciate your help. This is an inheritance and I’m not the original owner so I’m unsure of the name of the stone it’s SUPER LARGE. Wonderful and the sterling chain is equally as nice selling as shown chain is signed 925. If you love being a bit UNIQUE. This is for you.