Vietnam's grading vocabulary is built around the kỳ nam versus trầm hương split covered in our Vietnamese agarwood origin guide, but that's only the first layer. Within kỳ nam, four traditional color-based grades rank the rarest material in the global agarwood trade, while ordinary trầm hương is divided using a separate, less standardized vocabulary that varies somewhat by region and source.
Two Tiers: Kỳ Nam and Trầm Hương
As covered in our origin guide, Vietnamese trade classification treats kỳ nam as a distinct category above ordinary trầm hương, not simply its highest grade. Kỳ nam is generally described as carrying unusually high oil content, to the point that genuine pieces are often soft enough to take a fingernail impression, and it commands a substantial price premium over even high-grade trầm hương. Within that top tier, the trade further subdivides kỳ nam by color, the system covered below.
The Four Kỳ Nam Color Grades
Vietnamese kỳ nam is traditionally divided into four color grades, commonly summarized in the trade in descending order of rarity and value: white, green-blue, yellow-brown, and black.
Bạch Kỳ Nam (white kỳ nam) is described as ivory-white to light gray, soft, and unusually oil-rich. It is the rarest and most expensive of the four grades. Thanh Kỳ Nam (green-blue kỳ nam) follows, described as blue-gray to greenish in color, also oily and soft, with harder pieces occasionally reported. Huỳnh Kỳ Nam (yellow-brown kỳ nam) is described as a golden brown to beeswax-like yellow, hard and heavy when fresh, becoming noticeably lighter as it dries. Hắc Kỳ Nam (black kỳ nam) sits at the bottom of the four, described as an indigo-black, tar-like color with a hard texture.
These descriptions come from trade and seller sources rather than an independently verified scientific classification, and as with other qualitative grading language in this hub, treat specific color-grade claims on a given piece with the same scrutiny covered in our buying guide.
Trầm Hương's Broader Grade Categories
Outside kỳ nam, ordinary trầm hương is divided using terms that vary somewhat by region and by which source you consult. Our origin guide describes the commonly cited broad categories as trầm rế, trầm kiến, and trầm tóc, generally in descending order of resin content and accumulation time. Other regional sources, particularly around Khánh Hòa, also use terms such as trầm tốc and trầm chìm to describe broadly comparable tiers. This terminology overlap is not a contradiction so much as a symptom of the same underlying issue covered next: there is no single, official vocabulary that every seller and region uses identically.
Want to see how these terms compare to the trade's broader sinking-test and saturation vocabulary?
How Agarwood Is Graded: A Complete GuideWhy There's No Official Government Standard
There is currently no official document from Vietnamese state agencies, or any other governing body, formally establishing standards for classifying and grading agarwood. In practice, evaluation tends to rest on a consistent set of criteria, origin, scent intensity, scent type, shape, size, color, weight, specific gravity, and purity, along with which species produced the wood, but the specific thresholds and terminology applied to those criteria are set by individual sellers, regional convention, and industry bodies such as the Vietnam Agarwood Association rather than by government regulation.
Modern Lab Certification: AGALAB and Similar Bodies
Private testing laboratories have stepped into part of the gap left by the absence of an official standard. AGALAB, a Vietnamese agarwood testing laboratory, uses a five-criteria grading system and issues a "Grade S" designation, standing for sinkable natural agarwood, on its premium certificates for material that meets that classification. This kind of private lab certification gives buyers an additional, more standardized reference point beyond a seller's own grade claim, though it's worth being clear about what it is: a private laboratory's assessment against its own published criteria, not a government-backed guarantee.
What This Means When You're Buying
For buyers, the practical takeaway is that Vietnamese grading terminology, kỳ nam color grades included, functions as a detailed but non-standardized vocabulary rather than a fixed, government-audited scale. A seller's specific color-grade or trầm-tier claim is meaningful information, but it rests on that seller's own judgment and reputation. Where available, third-party lab certification from an established testing body adds a useful layer of verification, and the home checks covered in our authenticity testing guide remain a practical baseline regardless of what grade name is attached to a piece.