Chénxiāng (沉香) — Agarwood

Chénxiāng (沉香, "sinking fragrance") is the resin-saturated heartwood produced by trees of the genus Aquilaria (and related genera) when they respond to wounding, infection, or stress. The tree produces a dark, dense, aromatic resin — the resin itself is chénxiāng. Not all Aquilaria trees form it; formation requires a specific pathological response, making genuine agarwood inherently rare. China's classical literature ranks it highest among all aromatics: as recorded by Lǐ Shízhēn (李时珍) in the Běncǎo Gāngmù 《本草纲目》 (1578), "agarwood is the chief of all aromatics; no other material surpasses it in subtlety."

How does chénxiāng form?

Aquilaria trees grow throughout southern China, Southeast Asia, and South Asia. In a healthy specimen, the heartwood is pale and odourless. When the tree is wounded — by insects, fungi, lightning, or injury — certain species mount a defence response: they saturate the wound site with a dense, dark, aromatic resin. This resin-wood composite is chénxiāng.

Formation can take decades. Some pieces derive from trees that fell naturally and were resin-saturated over a century or more in forest soil (熟结 shú jié, "mature formation"). Other pieces are cut from living trees (生结 shēng jié, "living formation"). In contemporary plantation cultivation, growers artificially wound trees to trigger resin production — a process that accelerates formation but typically produces lower density and less complex fragrance than wild material.

TL;DR: Resin only forms after wounding; no wound = no agarwood. Wild formation takes decades to centuries. Plantation-induced formation typically yields lower grades. Aquilaria sinensis (Hǎinán/Guangdong) and A. crassna (Vietnam) are the most prized species for the Chinese market.

What are the grades of chénxiāng?

Water-sinking grades

The primary field-grade test for chénxiāng is density: resin-saturated wood is denser than water. Three categories:

Sinking-grade (沉水香 chénshuǐ xiāng) is the reference point for premium material. Note that the sinking test alone is insufficient for authentication — adding weight to inferior wood is a common fraud technique.

Official Chinese grading (LY/T 3223-2020)

China's forestry industry standard, implemented in June 2021, establishes five grades: special grade (特级 tèjí), grade 1 (一级 yī jí), grade 2 (二级 èr jí), grade 3 (三级 sān jí), and grade 4 (四级 sì jí). Grading assesses resin content, fragrance character, density, and appearance.

Qínán (奇楠) — a category apart

Qínán (奇楠, also written 琪楠; Japanese: kyara 伽羅) is not a grade of chénxiāng — it is a distinct category with different physical and aromatic properties. Key differences:

Classical Chinese sources note qínán must form in a living tree — it is not found in fallen timber. Wild genuine qínán is now vanishingly rare. Hǎinán and central Vietnam (Nha Trang coast) are the historically recognised sources.

TL;DR: Sinking grade = baseline quality. Qínán = entirely separate category above regular grades — soft, waxy, multi-toned fragrance. Genuine wild qínán is museum-rarity material; most market "qínán" is premium chénxiāng misrepresented.

Where does the best chénxiāng come from?

The regional hierarchy was established in classical Chinese sources. Lǐ Shízhēn's Běncǎo Gāngmù (1578) records: "Among all origins, Hǎinán is the finest — specifically Wàn'ān (万安) and Lí Mountain (黎母山); these are the best in the world."

Wild Hǎinán A. sinensis is now commercially extinct — centuries of demand destroyed the old-growth population. What reaches the market as "Hǎinán chénxiāng" today is plantation-grown or antique reclaimed material. Authentic wild Hǎinán pieces are found only in collections and museums.

All Aquilaria and Gyrinops species have been listed in CITES Appendix II since 2004, restricting international trade in unprocessed material.

How is chénxiāng used?

Incense: Direct burning (点燃, diǎnrán) of chips or powder. The premium method is indirect heat (隔火熏香 gé huǒ xūn xiāng): charcoal buried in incense ash, a mica plate over it, and wood chips placed on the mica — the wood heats to 80–120°C without combustion, releasing fragrance without the harshness of burning.

Wearables (文玩): Carved beads and pendants develop bāojiāng (包浆) patina with wear — the surface darkens, resin redistributes, and fragrance deepens with skin contact. Comparable to huánghuālí wood beads.

Traditional medicine: Chénxiāng is a material medica substance in the Shénnóng Běncǎo Jīng and subsequent Chinese pharmacopoeias — used for digestive disorders, pain, and as a Qi-regulating herb.

How to authenticate chénxiāng

• Water test: Sinking-grade pieces sink or hover at the surface. Not conclusive alone (weights can be added).
• Heat test: Hold near a warm bulb or use indirect heat — genuine resin releases fragrance at low temperatures. Inferior wood or artificial scented material smells synthetic or fails to release at low heat.
• Cut surface: Fresh cut shows dark resin veins embedded in lighter wood matrix. Uniformly dark pieces have been dyed.
• Knife test: Genuine sinking chénxiāng is hard and brittle; shavings curl and fragment. Qínán specifically is soft and waxy — it will dent rather than fragment.

Related

• Chinese Incense (香) — History and Culture
• Tánxiāng (檀香) — Sandalwood
• Incense Forms
• Xiānglú (香炉) — Incense Burners
• Huánghuālí (黄花梨) — same bāojiāng concept in wood beads

FAQ

What is chénxiāng? Chénxiāng (沉香) is resin-saturated heartwood produced by Aquilaria trees in response to wounding or infection. The name means "sinking fragrance" — high-grade pieces are denser than water. It is China's most prized aromatic material, used in incense, wearable beads, and traditional medicine.

What is qínán (奇楠) and how does it differ from regular agarwood? Qínán (奇楠, Japanese: kyara) is a distinct category above regular agarwood. Unlike hard, brittle regular chénxiāng, qínán is soft and waxy. Its fragrance is more complex — simultaneously sweet, bitter, spicy, and cool. It forms only in living trees and is extraordinarily rare. Most market "qínán" is misrepresented regular chénxiāng.

Why does Hǎinán agarwood command the highest prices? Lǐ Shízhēn's Běncǎo Gāngmù (1578) placed Hǎinán origin at the apex of the regional hierarchy. Wild Aquilaria sinensis from Hǎinán is now commercially extinct — centuries of harvesting destroyed old-growth trees. Today's Hǎinán-labelled material is plantation-grown; genuine wild Hǎinán pieces are collection-level.

What does the sinking test prove? That resin content is high enough to exceed water density (1.0 g/cm³). This confirms significant resin saturation but does not authenticate origin or rule out fraud — adding weight is a known adulterant. Use sinking as a necessary, not sufficient, quality indicator.

Is agarwood legal to buy and sell? Yes, in worked form. All Aquilaria spp. are CITES Appendix II since 2004 — international trade in raw unprocessed timber is regulated. Finished products (incense chips, carved beads, powder) can be traded legally; documentation requirements vary by jurisdiction.