Diamond Engagement Rings
Sapphire Engagement Rings
Emerald Engagement Rings
Ruby Engagement Rings
Rings
Earrings
Necklaces
Brooches
Bracelets & Bangles
Cufflinks
Pendants
Chains
Tie Pins
Lockets
Charms
Signet Rings
Seals
Curiosities
UK / £
USA / $
AU / $
Experts since 1975
-
Your Shopping Bag is empty
Free Worldwide Delivery
View All
Diamond
Sapphire
Emerald
Ruby
Onyx
Onyx is an opaque black variety of polycrystalline chalcedony quartz.
Back to Glossary
Enter the World of AJC
Read. Watch. Shop. Learn. All in one place.
Latest Finds
What's Hot
Expert Picks
The Archive
Sale
Eras
Collections
Contact
Book Appointment
Join VIP