Research.
So I was in London last week and it was splendid of course and one of the most splendid things I got to see was the Victoria and Albert Museum, the V&A. This museum is a gorgeous sprawling complex with six floors and has absolutely everything in it, from Rodin to Yohji Yamamoto, and the whole thing is packed with visitors from thirty-seven countries EXCEPT the sixth floor, where the stairs don't actually go, which can only be reached by one lift which is tucked away in the backwater corner of some exhibit that nobody likes. But I found it. It is entirely devoted to Ceramics: Materials and Techniques.
Love it.
The point is, I need some more research here, and I only used one source, really, to tell me how to dig my pit, so other nine (ugh) have to be devoted to something else, so I'm learning a bit about the history of ceramics and clay in general. Here's what I learned from the signs and captions on the pieces.
The earliest known ceramics come from China, around 5000 BC. Kiln-fired ceramics were first prevalent during the Han dynasty, which began about 200 BC. Kilns produced ceramics for architecture, funerals, and everyday use, both functional and decorative. (The most common use of non-functional ceramics was placement in tombs and use during burial.)
High-fired stoneware, what we would call bisqueware, was pioneered also in China around 500 AD. Kaolin-rich clay (see earlier entries) turned whitish when temperatures above 1100 C- remember it's Europe - were reached. This is a great deal hotter than my little pit, almost the temperature needed for modern high-firing, which melts glaze to a piece and seals the pores. And the Chinese were all about glaze; as soon as they could make it reliable, they glazed all their ceramics.
Not so in Japan, at least in early Japan. The Japanese started making decent ceramics, or at least ceramics that have survived to now, around 400 AD. These early ceramics were known as Sue wares and were high-fired but unglazed. Sometimes they had a natural ash glaze, which is exactly what my pieces have - unintentional, unplanned, the ash somehow gets in amongst the ware and gives it that luster which I prize so highly.
Here are some.
And here's mine.
Resemblance achieved!