Jade Type A, B and C — the only classification that matters

No other gem has such a wide gap between untreated and treated prices. Two pieces sitting in the same case, looking much alike, can differ by twenty times in value.

Jadeite and nephrite are different minerals

The English word jade covers two entirely separate stones.

Jadeite is the valuable one, sourced mainly from Myanmar. It reaches vivid emerald greens, is more translucent, and has a fine icy granularity to its texture.

Nephrite is far more common, from China, Canada and New Zealand. It usually shows a muted or greyish green, is tougher but less translucent, and costs a great deal less.

Both are legitimately called jade. When buying, always ask which one you are looking at.

The A, B and C system

This classification says nothing about quality. It describes the level of treatment, which matters more.

Type B and C are not illegal when disclosed. The problem is that they frequently are not, and get sold at Type A prices.

Note that Type B has been acid-etched, which leaves the internal structure porous. The piece is physically weaker, not merely less durable cosmetically.

Warning signs

Nothing visible to the naked eye is conclusive, but there are signals.

Colour that is uniformly vivid across an entire piece with no natural variation or veining usually means dye. Almost all natural jade is uneven somewhere.

Shine a torch through it. If the colour appears to run in threads along fine fractures, that is dye that has wicked into cracks rather than colour in the stone itself.

Tap two pieces together lightly. Type A rings clear and bright; Type B sounds duller because the resin damps it. This only works if you have heard genuine material before.

For any significant purchase, ask for a report. GIT tests specifically for this and states the type explicitly. The fee is trivial against a difference that can run into thousands.