Zircon buyer’s guide

What you can see

Look through the table with a lens. On many zircons the pavilion facets appear doubled. That doubling is birefringence, and it is one reason zircon is not diamond, which is singly refractive. Colorless, blue, yellow, and brown stones are all in the trade. Blue is commonly produced by heating brown material. The listing should say heated when that is the case.

Some zircons are metamict: radiation from traces of uranium has damaged the crystal over geologic time, lowering hardness and density. Those stones are usually green or brown and are less suitable for a ring. A bright blue or colorless jewelry zircon is normally the high type.

Care

Hardness is below sapphire, and zircon can abrade at the facet edges if it is worn against harder gems in a box. Store it separately. Avoid sudden heat and aggressive ultrasonic cleaning, especially on heated stones.

Because density is high, a zircon of a given face-up size weighs more than a sapphire of the same measurements. If a “large” zircon has a modest carat weight, check the depth. A shallow stone can look big and weigh little.

How we name it

We say zircon when we mean zircon. We do not use the name as a substitute for diamond, and we do not use cubic zirconia in these listings. If you want a durable colorless stone for daily wear, ask us whether sapphire or another gem in stock is the better comparison. Zircon is worth buying for its own fire, with honest care.