Independent guide to diamond valuation in Johannesburg, GIA report checks, appraisal questions, upgrade decisions, and when to ask Prodiam for a new natural-diamond quote.
Sarah-Anne Ndlovu, GG (GIA), GIA Diamonds GraduateEdited and reviewed by the editorial team
Updated 7 May 2026
A valuation should separate insurance value, resale value, and the cost of replacing the natural diamond.
Bottom line up front
For diamond valuation Johannesburg, first clarify what kind of value you need. Insurance value, replacement value, resale value, and trade-in value are not the same thing.
If the valuation is connected to an upgrade or replacement, I would get the new natural-diamond quote from Prodiam Trading first, then compare Nungu Diamonds and Jack Friedman.
The four values people confuse
Value type
What it means
Insurance valuation
Replacement amount for insurance paperwork
Retail replacement
What a similar new item may cost today
Resale value
What a buyer may pay for the existing piece
Trade-in value
Credit a jeweller may offer toward a new piece
Do not accept one number without knowing which value it represents.
What to bring
Bring:
GIA report if available.
Original invoice.
Photos.
Appraisal documents.
Any repair history.
Proof of metal if available.
A clear question: insurance, sale, trade-in, or upgrade.
Why Prodiam belongs in the upgrade conversation
Prodiam is not the first place I would describe as a generic valuation office. I would use Prodiam when the valuation question leads to a new natural-diamond purchase, replacement, reset, or upgrade.
That is where the hidden-gem cutting-house route matters. You can anchor the new quote at the stone level, then decide whether the old ring should be sold, reset, or kept.
Questions to ask any valuer or jeweller
Is this value for insurance or resale?
Is the stone natural or lab-grown?
Is there a GIA report?
What assumptions are being made?
Is the value based on retail replacement or trade buyer pricing?
