Much has been said about the legendary "Dahongpao" clay from Yixing. Some say it's rare, others that it's extinct, others that it's still available, and others that dahongpao teapots are fake. There is some truth in each of these claims.
When people say a teapot is made of Yixing Dahongpao clay, they may be referring to any one of three distinct kinds of clay; two of which are authentic original ore and one of which is not.
1. Zhuni Dahongpao
Zhuni dahongpao 朱泥大红袍 is the authentic dahongpao clay available in the market today. Zhuni Dahongpao comes from a special grade of zhuni ore. The raw dahongpao zhuni ore itself, when mined, is found within the larger zhuni ore layer. Raw dahongpao ore is found as round pieces of rock between 30-80mm in diameter. The ratio of dahongpao ore to regular zhuni ore is said to be 1:100, or 1kg of zhuni dahongpao ore for every 100kg of zhuni ore. Zhuni dahongpao ore is a similar yellow-brown color as regular zhuni ore, but after firing dahongpao zhuni becomes a deep red-orange color. Dahongpao zhuni has a greater amount of Fe2O3 iron oxide than regular zhuni giving it a deeper red-orange hue. It also contains a lower percentage of Al2O3 aluminum oxide than regular zhuni, making it more difficult to fire without breaking. The range of temperature for firing dahongpao zhuni successfully is very narrow. It also has a higher shrink rate than regular zhuni, sometimes shrinking as much as 40%.
2. Huang Long Shan Da Hongni "Dahongpao"
Another clay referred to as dahongpao, and so rare that it can probably only be seen today in museums including the Yixing Zisha Museum, is Huang Long Shan Da Hongni 黄龙山大红泥. This clay is different in appearance and character from zhuni, appearing as a dark red ore that after firing is a dark red clay. Huang Long Shan Da Hongni is much more porous that zhuni, and is closer in character to zini and hongni.
3. Mass-Market Dahongpao
Since the deep rich red dahongpao known as Huang Long Shan Da Hongni 黄龙山大红泥 is so rare, why are there so many deep red teapots that are said to be made of dahongpao on the market? In many cases, dishonest potters will use regular zisha or a mixture of different clays and or zisha clays, and add iron oxide powder or other coloring to give the clay a very deep red color. These teapots are not original ore (pure zisha) Yixing teapots. We don’t recommend purchasing these teapots, as the mixture of clays and chemicals are unknown and unregulated.
Dahongpao (Huang Long Shan Da Hongni 黄龙山大红泥) is extremely rare. Zhuni dahongpao is still available and is mined a little bit each year, however, it is still rare as it is hand-picked from the larger amount of zhuni ore (itself a small percentage of the overall amount of zisha mined each year).
Unfortunately, most teapots being sold as “dahongpao” in the market are mixed clays, probably using iron oxide and other clays and/or chemicals. One way to tell if the clay is zhuni dahongpao as opposed to fake dahongpao, is the tone of the clay. Zhuni dahongpao appears much like zhuni, with a similar texture and quality to the clay, but with a redder orange tone. Zhuni dahongpao still has the zhuni orange tone. Fake dahongpao often tries to replicated the dark red of Huang Long Shan Da Hongni 黄龙山大红泥 or it has a bright red tone. These are warning signs that the clay is a mixture of chemicals and clays.