First in History，Qing Yixing Teapot of Black Dotted Clay Found in US 清代原矿黑星土紫砂壶在美国首次出现
We believe the 3 Tripod Compass Teapot marked YANG Pengnian of Qing dynasty are of Black Dotted clay raw Ore. However, Black Dotted clay raw ore is extremely rare and teapots made in modern times of claimed Black Dotted clay raw ore or not are of man made by adding manganese particles.
Black Dotted Clay： Raw Ore or Man-Made with Manganese?
Black Dotted clay, or Black Star clay or sand, usually refers to one of the Mixed Purple clays made in the 70-80s, by adding Manganese particles. After firing, it has a characteristic of small black dots on the surface. If you search the internet with the Chinese phrase 黑星土 or 原矿黑星土, it will show up teapots all over your search results. They are unanimously all teapots made with mixed purple clays by adding Manganese particles. The question is does Black Dotted clay of raw ore ever exist? Yes, it is said in fact Black Dotted clay of raw ore did exist in the early days (when?). Only it is just extremely rare and so rare no one have claimed to have seen it. That's the exact reason why Black Dotted clay is one of the two legendary Zisha clays.
Black Dotted Clay artificially made with Manganese
Qing Yixing Tripod Compass Teapot marked YANG Pengnian is of Black Dotted Clay from Raw Ore
In examining my teapot marked YANG Pengnian, I found that the craftsmanship, color and texture of the clay all closely match that from the museum. We believe this teapot must be a genuine authentic one made in the Qing dynasty by the original author YANG Pengnian.
screenshot of teapot from Shanghai museum
Upon close examination, I found that its clay is filled with black dots on its surface - characteristics of Black Dotted clay man-made with manganese. Yet it is different and more beautiful. Because man-made Black Dotted clay only happened in the 1970-80s and unlikely happened in the Qing dynasty, we therefore believe this must be of Black Dotted clay raw ore.
Side by side comparison: left of Black Dotted clay man made with manganese vs right Black Dotted clay Raw Ore
15x magnification Black Dotted clay man made with manganese
15x magnification Black Dotted clay
We believe the 3 Yixing clay Tripod Compass teapots marked YANG Pengnian are of Black Dotted clay raw ore and the rest of acclaimed Black Dotted clay teapots are of man made by adding with manganese particles.
Here are the sizes of the 3 tripod compass teapot marked YANG Pengnian
This teapot: h60mm, diameter of opening 64mm
The teapot of Shanghai Museum: h37mm, diameter of opening 58mm
The teapot of Huaian Museum: h37cm, diameter of opening 44mm