Jian Zhan Glossary: 22 Terms Every Collector Should Know
Short answer: this glossary defines the 22 Jian Zhan terms you will meet most often — the glaze patterns, the materials, the firing methods, and the vessel parts that collectors discuss. Each entry gives the English term, the original Chinese or Japanese word, and a one-sentence definition you can use with confidence.
Glaze Patterns
Jian Zhan — the Chinese name for the iron-bodied, dark-glazed tea bowl first fired in the Jian kilns during the Song Dynasty.
Tenmoku — the Japanese name for the same family of dark bowls; in international use it refers to the style, while 'Jian Zhan' names the origin.
Oil Spot / You Di — round, metallic iron crystals that appear to float beneath the glaze surface, prized for their shimmer.
Hare's Fur / Tu Hao — fine vertical streaks running from rim to center, the classic Song Dynasty pattern.
Partridge Feather / Zhe Gu Ban — mottled, overlapping iridescent patches resembling bird feathers, rarer than oil spots.
Yohen / Yao Bian — the rarest pattern: iridescent halos of blue, purple and green inside dark spots, considered a once-in-a-firing accident.
Kiln Change / Yao Bian — the uncontrolled transformation of glaze color and texture during firing; the source of 'one-of-a-kind' pieces.
Crystalline Glaze — glazes in which visible crystals grow during controlled cooling, producing flower-like or scale-like formations.
Materials & Body
Tie Tai — the iron-rich clay body that gives Jian Zhan its weight, dark color and heat retention.
Kaolin — the white-firing clay named after a village near Jingdezhen, essential to porcelain bodies.
Feldspar — the mineral that acts as a flux, melting the glaze into glass at high temperature.
Iron Oxide — the pigment behind every Jian Zhan color, from silver spots to rusty reds.
Firing
Reduction Firing — firing with restricted oxygen so the kiln atmosphere 'steals' oxygen from the glaze, drawing iron crystals to the surface. The defining technique of authentic Jian Zhan.
Oxidation Firing — firing with ample oxygen; predictable in color, and incapable of producing true oil-spot or hare's-fur effects.
1300°C — the working temperature range of high-fired Jian Zhan, where clay and glaze fuse into one vitrified body.
Kiln Sitter — the device or the artisan's judgment that ends a firing at exactly the right moment.
Wood Firing — firing with wood alone, where ash falls onto the pieces and becomes part of the glaze.
Vessel Parts & Shapes
Shukou — the constricted rim that traps aroma and steadies the pour.
Douli / Bamboo Hat Bowl — a wide, conical bowl shaped like a bamboo hat, favored for green tea.
General's Bowl — a large, deep bowl of maximum thermal mass, for bold teas and long sessions.
Foot Ring — the unglazed ring under the bowl; its color and texture reveal the true iron body and help confirm authenticity.
Collecting & Use
Seasoning — the slow development of the cup through use, as tea oils settle into the glaze's micro-pores.
Bloom / Patina — the soft sheen that appears on a well-seasoned cup, the visible sign of long devotion. How to build a bloom →
How to Use This Glossary
When you read a listing, a forum thread or a museum label, match the terms here to what you can actually see: pattern name, body, firing method, and shape. That four-part reading is how experienced collectors describe a cup in one sentence — and how they spot a piece that claims more than it shows. See every pattern in the Glaze Guide → | Browse the Knowledge Center →