Kasama Feldspar: A New Ceramic Resource

To coincide with 250 years of Kasama ceramics, the town has developed a new feldspar, as a fresh ingredient for its ceramic community

The principal resource of Kasama ceramics is its human stock of creativity. The large community of individual makers, together with its pottery businesses, galleries, and educational facilities. In combination they make the modern identity of Kasama ware.

But the origins of ceramics in Kasama are also in surrounding nature. The slightly stubborn Kasama clay that with skill can be shaped into distinctive forms. Also the town’s location on an artery to the capital.

In 2022 to coincide with 250 years of history of ceramics in Kasama, the town took a step forward in developing their geographical terroir by creating a distinct, local resource that can be used as an ingredient for glazes and surface decoration.

This is the Kasama Choseki (feldspar) that Kasama’s ceramic college and pottery union made together for use by the town’s ceramic community and beyond.

Kasama is known for pots, but also for its granite architectural stone. The imposing blocks of rock quarried in the Inada region of modern Kasama are one of Japan’s finest building materials. The national parliament, supreme court, and Tokyo station were all constructed using the granite, which is marked with spots of black quartz.

Inada granite found in Kasama is one of Japan’s finest building materials

The quarrying process leads to powdered by-product which until now was largely disposed of. But experiments over the past several years found it can be worked into a ceramic feldspar. This reduces waste, and opened a new palette in ceramic creation.

Kasama feldspar is similar in its geological components to Japan’s most famous such materials, but is distinctive in its high iron content (at around 1.1%). This both allows the Kasama ceramic community to work with a growing proportion of locally sourced materials, and places a new tool in their hands to fire unique works.

The Inada stone quarry

Feldspar is an element in making glazes. To demonstrate the possibilities, the Kasama Potter Tatsushi Nemoto has made a series of ‘swatch’ type pieces that show the textures and shades achievable using the new material. These can be seen in Islington Square in London, during the period of the temporary Kasama Potters display and retail shop.

250 years on from the first innovations in Kasama ceramics, the ideas and resources in its pottery community continue to take it forward. The new feldspar sets in train a new discourse between maker and materials in their town.

Swatch style pieces by using Kasama feldspar, by Tatsushi Nemoto