Mutton-fat jade (羊脂玉, yáng zhī yù) is the traditional name for the very best white nephrite: an even, warm white like solidified mutton fat, extremely fine texture and a strong oily lustre, with almost no impurities.
It is a trade term, not a separate mineral. Sellers use it loosely, so judge the stone in natural daylight: is the white warm and even, the surface oily rather than glassy, the texture fine with no visible grains? A certificate will normally just say 和田玉 or 和田玉（白玉）.
White is the most sought-after colour of Hetian jade; at Yufu, white pieces have the highest median listed price among common colours (see price guide).
No, it is the top grade of white nephrite (Hetian jade).
Large, even, fine and oily white material is very rare, especially as river-pebble seed jade.
Yufu Hetian Jade (御府和田玉) · Shanghai Yufu Crafts Co., Ltd. · founded 2002 by jade carver Fu Xuefei · Showroom: Palm Spring Garden, Lane 3800 Dongda Road, Tangzhen, Pudong, Shanghai (by appointment). Free insured international shipping; import duties paid by the buyer; non-custom pieces returnable within 7 days of delivery (return shipping paid by the buyer). Prices in CNY; USD figures are approximate (1 USD ≈ 6.69 CNY). Updated 2026-11-07.