Question 1

What does Old Mine mean for an emerald?

Accepted Answer

Old Mine is a trade term for Colombian emeralds thought to come from historic production, typically Muzo, rather than recent mining. It suggests the deep, warm green associated with older Muzo material. It is not a standardised laboratory grade and its use varies between dealers, so the description should be supported by provenance, appearance and a report confirming Colombian origin.

Question 2

Is a Muzo Old Mine emerald better than a new Muzo emerald?

Accepted Answer

Not automatically. Old Mine stones are often valued for their colour and history, and many buyers pay a premium for them. However, recent production from Muzo also includes fine stones, and quality varies in both. Judge each stone on colour, clarity, enhancement and cut, and treat the Old Mine description as supporting context rather than a guarantee of quality.

Question 3

Do Old Mine emeralds come with lab reports?

Accepted Answer

Many fine Old Mine emeralds are sold with reports from laboratories such as GRS, SSEF, Gübelin or GIA stating Colombian origin and the degree of clarity enhancement. Whether a report comments on the Old Mine description varies by laboratory, so read the wording carefully. For older stones, a recent report is useful because the extent of oil or resin can change over time.

Question 4

Are Old Mine emeralds oiled?

Accepted Answer

Most are, as with Colombian emeralds generally. Older stones may have been oiled several times over their life, and some are cleaned and re-oiled before resale. The laboratory report should state the extent of enhancement, from none or insignificant to significant. Stones with fine colour and minor or less enhancement are particularly rare and valued accordingly.

Old Mine Colombian Emeralds