Type A, B and C jadeite

“Grade A jade” appears in an enormous number of listings, and it is doing one of two jobs. It is either citing a real classification with a precise meaning, or it is a seller’s adjective borrowed from that classification because it sounds official. Distinguishing the two is worth a few minutes, because the real version answers a question about the material and the borrowed version answers nothing.

What the letters classify

A, B and C are trade-and-laboratory shorthand for what has been done to a piece of jadeite. They are a treatment classification, and that is the entirety of their content.

Type A — jadeite that has not been treated. The colour and translucency are the material’s own. Surface waxing, a traditional finishing step that fills microscopic pits and improves polish, is conventionally compatible with Type A because it is a surface finish rather than a structural intervention.

Type B — jadeite that has been bleached with acid to remove iron staining, which leaves the stone porous and weakened, and then impregnated under pressure with a clear polymer that fills the voids and restores both integrity and translucency. The material remains jadeite by composition. The object is substantially a composite. The process and the traces it leaves are the reason the classification exists at all.

Type C — jadeite that has been dyed. The green, lavender or red is added colour, sitting in fractures and grain boundaries rather than in the mineral’s structure.

Type B+C — both: bleached, impregnated and dyed. Common, since a stone poor enough to justify one treatment usually justifies the other.

What the letters do not classify

This is the part the listings rely on you not knowing.

The letters say nothing about quality. A dull, pale, cloudy, cracked piece of jadeite that nobody has treated is Type A. A vividly green, flawlessly translucent, beautifully carved piece that has been impregnated is Type B. If you rank the two on appearance, the B wins; if you rank them on the classification, the A wins. They are measuring different things, and the classification is not measuring beauty.

They say nothing about colour, size, translucency, or workmanship — the four things that actually set the price of jadeite in the trade.

They apply to jadeite. Not to nephrite, which is classified and described differently; not to serpentine, quartzite, marble or glass. “Grade A jade” attached to a green stone that turns out to be serpentine sold under a jade trade name is a category error twice over: the material is not jadeite, so the classification does not apply, and the letter was never a compliment in the first place.

And “AAA”, “5A”, “AAAAA” and “premium grade A” are not extensions of it. They are seller inventions with no defined referent, no issuing body and no criteria. The classification has three letters and a compound; anything with more As is decoration.

What you can establish

WHAT YOU CAN TELL — a listing that says "Grade A"

  · Named as a treatment class, with a report
      → a claim that can be checked
  · "Grade A" alone, no report, no lab
      → a marketing string. Establishes nothing
  · "AAA" or "5A" → no defined referent at all
  · Applied to serpentine, quartzite or glass
      → the classification does not apply
  · Colour pooled in cracks under a loupe
      → dye; consistent with Type C
  · Type A or Type B on this object? → NOT
      DETERMINABLE at home. Needs spectroscopy

Why the classification exists

Because impregnation is invisible and consequential.

A skilled examiner can often suspect Type B material from a slightly waxy or resinous surface lustre, a subtle over-uniform glow, or a chalky fluorescence under ultraviolet light. None of that is conclusive, and a good piece of Type B material can pass visual inspection by anyone. Meanwhile the difference in the object is real: polymer ages where jadeite does not, and impregnated material can yellow, cloud or develop fine surface crazing over years, on top of having had material removed by acid in the first place.

So the trade needed a vocabulary for a distinction that eyes cannot make, and the letters are it. The treatments themselves are legal and routine, and disclosed as a matter of course further up the supply chain. What goes wrong, when something goes wrong, is nearly always in the description rather than in the workshop: the disclosure is present at wholesale and absent by the time a listing is written.

What settles it, and what does not

Resin is detected by infrared spectroscopy, which distinguishes polymer-bearing from polymer-free material directly, and dye by a combination of magnification and spectroscopic examination for the absorption pattern a dye produces and a mineral does not. Both are ordinary procedures in a properly equipped laboratory and neither has a home equivalent.

Which means the letter in a listing is only as good as the document behind it, and there usually is none. A one-line assertion of Type A on a product page is not a test result; the difference between that and an actual laboratory report is the difference between a claim and evidence.

There is also an economic reality worth naming plainly. Jadeite of a quality where the A-versus-B question carries real money is not the material from which thin, flat, inexpensive tools are made in volume. For most tools the honest expectation is that the object is not jadeite at all, in which case the classification is irrelevant rather than violated.

The limit

You can read a listing critically: you can tell whether the letter is being used as a treatment class or as a compliment, you can notice that it has been applied to a material it does not cover, and you can sometimes catch dye under a loupe.

You cannot determine the class of the object in your hand. Not by hardness, not by weight, not by feel, not by looking. Type A and Type B jadeite have the same composition and nearly the same properties, which is exactly why somebody bothered to make the second one — and the only reliable answer comes from an instrument that costs more than the tool.