Value of Natural Cubic Zirconia in Vintage Jewelry - Expert Advice

Question
Hi Peter,
I have an old 9ct ring marked in Birmingham in 1943. It's a Claddagh design mounted with CZ (also marked) and a stone which I think is garnet. My question is about CZ, since the ring dates from 1943, CZ has to be natural and I've heard this mineral is quite rare and has not been widely used in jewellery. Can you give me any idea on how much does it add to the ring's value? Thank you!

Answer
Hi Leah,

CZ has been around a long time. It was discovered in 1892 as a natural form of zirconium oxide called baddeleyite. It is a rare mineral and very unstable. The synthetic stabelized single crystal cubic zirconium was introduced in 1930 and manufactured successfully in the 1960's. I don't believe that the stones were not even called CZ in 1943. If in fact it is the natural form I would be very surprised. Check the manufacture date and why would it be identified as 'CZ'? If it is the rare form of natural zirconium Oxide it would be more valuable than the synthetic CZ but is not in very much demand so it would be more a collectors desire. I would be valuable only to them but it is more valuable. How much would depend on the market.

Peter