Shop › Apatite Signet Image 1 of 10 Image 2 of 10 Image 3 of 10 Image 4 of 10 Image 5 of 10 Image 6 of 10 Image 7 of 10 Image 8 of 10 Image 9 of 10 Image 10 of 10 Apatite Signet $250.00 ~1ct Blue Apatite set in hallmarked sterling silver. Hand carved, sand casted, and set. Size 5.75-6. It's a tight fitting 6. Add To Cart Added! ~1ct Blue Apatite set in hallmarked sterling silver. Hand carved, sand casted, and set. Size 5.75-6. It's a tight fitting 6.