What is Type A jadeite?
Jade Education
What is Type A jadeite?
Type A is the one grade of jadeite that has not been chemically altered. Everything else you read on a seller's page has to be measured against that single letter.
The short answer
Type A means untreated.
Type A jadeite has had nothing added to it and nothing taken out. The stone was cut and polished, and that is essentially the whole list: no acid, no resin, no dye.
One clarification, because it comes up constantly: a light coat of wax after polishing is standard finishing for jade and still counts as Type A. Wax is a thin surface layer that wears away. That is a completely different thing from polymer impregnation, where resin is forced deep into the stone to change how it looks.
And Type A is not a quality grade. It says nothing about how beautiful or valuable the stone is. It is a statement about what has been done to it.
The grading system
Why the letter exists at all.
Two stones can look identical in a photograph and be graded a world apart. The trade needed a short, blunt way to describe what had been done to a piece, so the A / B / C system was built entirely around treatment.
Type A
Natural
Untreated jadeite. No bleaching, no polymer filling, no dye. Cutting and polishing only.
Type B
Bleached & filled
Acid strips out brown patches, then clear resin is soaked in to restore transparency. That resin soak is polymer impregnation.
Type C
Dyed
Color is introduced with dye. The stone was never that green; the dye is what you are seeing.
Type B + C
Bleached, filled & dyed
Both treatments on one stone: false clarity and false color. The lowest of the treated categories.
The science
What Type A actually measures.
Natural jadeite has a specific mineral signature. Gemological laboratories test for it, and those numbers are how a stone is identified rather than guessed at.
Type A material shows no absorption pattern from resin or polymer when tested with infrared spectroscopy. That is the decisive test laboratories rely on, because a filler can be invisible to the eye and still obvious to the instrument.
Specific gravity matters too. Bleaching opens the stone's structure and polymer is lighter than jadeite, so treated stones often read slightly below the natural 3.34. A low reading is a strong hint of treatment, never on its own a verdict.
Durability
Why untreated matters for the long run.
Jadeite is exceptionally tough. It is made of interlocking crystals, which is why it survives generations and why it was used for tools and weapons before it was used for jewelry. Toughness is not the same as hardness, and it does not make jade immune to damage, but very little else in a jewelry box takes a knock as well.
Type A keeps that structure intact. Treated stones do not. Bleaching dissolves part of the material and leaves pores behind; the resin that fills them is softer, and it can yellow, cloud, shrink, or leach out over years. Dye sits where it was pushed in and can fade in sunlight or move into cracks.
A treated stone can look wonderful on the day you buy it. The question is what it looks like in ten years.
Honest value
Type A is not automatically expensive.
A pale, opaque, heavily fractured Type A stone can be worth less than a fine piece on almost any other measure. Grade and quality are separate conversations: the letter tells you the stone is honest, not that it is rare.
What Type A does is protect the part you cannot see. When everything else is equal, natural material carries the premium, holds value, and can be resold on its merits. Treated jadeite should never be priced like untreated jadeite, and undisclosed treatment is the most common way buyers overpay in this market.
Type A is the only grade of jadeite we will ever put our name on.
Keep reading
More on jade, from the stone up.
Every piece we sell is natural Type A.
No treatments, no dyes, and the certificate is included rather than sold as an add-on.