Natural versus treated black diamonds
Natural carbonado black diamonds have an opaque polycrystalline structure formed through an unusual geological process. Treated black diamonds are colourless or heavily included rough stones darkened by irradiation or heat. Both are real diamonds. Treated stones must be disclosed; if a seller cannot confirm treatment status, treat that as a red flag.
Simulants and how to spot them
Black moissanite and black cubic zirconia are both sold as substitutes. Moissanite is a separate mineral; zirconia is synthetic. Neither is a diamond. A thermal conductivity test or lab inspection confirms natural diamond status. For earrings below R2 000 total, simulants are common in mass-market retail.
Setting and metal pairings for earrings
White gold and platinum frame black stones with high contrast. Rose gold creates a warm, current look. Yellow gold reads as more traditional. Stud earrings with bezel settings protect the girdle from snags in hair. Drop earrings need a secure bail and chain link that can support the stone weight.
Prodiam and certified diamond sourcing
Prodiam works with certified natural diamonds in Bedfordview, Johannesburg. If you are sourcing stones for custom earrings or need guidance on what you currently own, the team can assist. Contact the Prodiam team or +27 74 702 1976.
Decision table
Use the details, not a shortcut.
| Stone type | How to confirm | Resale note |
|---|---|---|
| Natural carbonado | Gemmological inspection, lab report | Rarer, small secondary market |
| Treated black diamond | Certificate noting treatment | Lower price, limited resale |
| Black moissanite | Thermal test, refractive index | Not a diamond; no diamond resale value |
| Black cubic zirconia | Hardness test, thermal test | Simulant; negligible resale |
| Black spinel | Lab ID | Gemstone, not a diamond |
Direct answers
Common questions
Are black diamond earrings real diamonds?
The stone may be a real diamond, a simulant, or something else entirely. Ask for confirmation of stone type and treatment status. A lab report resolves the question.
Do black diamonds cost less than colourless diamonds?
Treated black diamonds are priced below colourless natural diamonds of similar carat weight. Natural carbonado is priced higher within the black diamond category but typically still below high-quality colourless.
What metal is best for black diamond earrings?
White gold or platinum gives maximum contrast against the black stone. Rose gold creates a warm paired look. Both work well in stud and drop designs.
How do I care for black diamond earrings?
Clean gently with warm soapy water and a soft brush. Avoid ultrasonic cleaners for treated stones or stones with fractures, as vibration can extend existing cracks.
Can Prodiam help with black diamond earrings?
Prodiam focuses on certified natural colourless and near-colourless diamonds. For specific questions about black diamond sourcing, contact the team to discuss your requirements.