A Site Specific Glaze: Tree Granite.

I love the idea of making self-referential ceramics, where the ‘self’ represented are raw earth materials and more specifically the particular geographic location where they were gathered. I want to gather just enough glaze materials to create a small batch of a site specific glaze, applied to several cups to use at our cabin.

I want to sip my morning coffee out of a cup that literally represents the ground I am standing on, the ground that has helped nourish and support all of the plants and animals comprising the beautiful biome surrounding me.

Tree Granite is the name I’ve given to a very specific granite next to a 320sf cabin my husband and I purchased in 2021 (and are still in the process of rehabbing). At some point this granite was unearthed when a large Ponderosa Pine tree toppled over, revealing its roots still clutching large pieces of the ~50 million year old rock.

I gathered a sample of small, loose pieces of this granite and sent it to a lab for chemical composition analysis. With this information, I have been developing several food safe glaze recipes to test and will eventually select a favorite from these tests.

All granites contain quartz and feldspar, which are both essential glaze minerals. Tree granite also contains mica and an occasional tiny garnet or two. I wanted to see how this rock might express itself in a very simple glaze. It has almost no mineral content that could act as a colorant. The most basic version of a tree granite glaze that I could develop was a glossy clear (bottom, left). Here is the recipe for the clear test glaze. It also contains calcium carbonate and a bit of clay.

I added a bit of tin oxide as an opacifier to another version I tested (above, right). The result was a milky, glossy white glaze that I find so charming. For a bit of self-referential fun, I added the glaze to a tumbler that was embedded with a small piece of tree granite, fired into the porcelain clay.

I’m eager to keep exploring, developing, and using local rock glazes in my work. Feel free to message me with any questions!