The sediment has been ground by tectonic plates scraping against each other. It's very fine-grained and after it's applied to the clay it dries and contracts and peels up like a dried riverbed cracks but then, in the kiln, it melts and relaxes back down. More about the material here.
Converging and Diverging Plate Boundaries on Porcelain
Costa Rican Accretionary Prism on Porcelain
Costa Rican Cup
Costa Rican Subduction Cup
Folding Fracturing Fissuring on porcelain
5" x 2.5"
On porcelain clay, a good example of how the Costa Rican Accretionary Prism sediment looks when applied thinly and thickly. Center of seaglass. Rim and foot glazes assembled from refined materials.
4" x 2"
On porcelain, click for larger image to read words. Brown glaze is from the Costa Rican Accretionary Prism. Center of seaglass, rim and foot assembled from refined materials.
8" x 4"
On porcelain. Costa Rican sediment contracted and curled before it melted, in contrast to smooth, semi-sheer Earth crust. Seaglass center. Click multiple times to see back and side views and read words.
5.5" x 3"
On porcelain clay, "Subducting friction forcing divergence at Mid-Atlantic Ridge". Interior from Costa Rican accretionary prism and exterior of rock slurry from Kane Fracture Zone, applied to a surface that had been chattered when the bowl was leather-hard. Rim and foot of glazes assembled from refined materials.
7.5" x 2.25"
On porcelain clay, seaglass center surrounded by Mid-Atlantic Ridge and Havre volcano pumice/mud. Rim and foot of glazes assembled from refined materials.
A clay slab with inner rectangle dipped into rock slurry from Mid-Atlantic Ridge (area called Kane Fracture Zone) and hung by stainless steel cable wrapped around stones from the rift valley in Iceland -- playing with continuity of that long ridge that keeps spreading. Frame is glazed with ladles from 6 buckets from location extremes of north, south, east and west plus high-carbonate and high-silica samples.
Writing includes a description about the Kane Fracture Zone material.
11" x 11".
Across continents, across time zones, the world upside-down, two cohorts find each other and co-create; His form, Her glazes. No! Earth's glazes -- Gaia's glazes. Just the evidence of materials changed in a kiln. Thanks to Brian Gartside!
5/25" x 2.5"
Says, "Costa Rican accretionary prism subducting, folding, fracturing, fissuring". Rim glaze assembled from refined materials. Center of sea-glass.
6" x 2"
With coordinates. Rock slurry is thin and transparent on the back, applied more thickly on the interior chatter-patterned area. Glazes assembled from refined materials are celadon and copper green (Oribe).
Some WOW stuff came from the kiln over twenty years of melting muds and rocks. Some I photographed and have assembled into a set of twelve cards you can see as thumbnails and a slideshow here. Cards are blank inside EXCEPT a thirteenth with a LEGEND inside -- it refers to numbers on each card.
NOTE about shipping: $7.50 is the cost of one in a Flat Rate USPS box but website only calculates UPS. If you need shipping, I'll subtract the difference between $7.50 and the UPS charge so you'll pay the lower cost. If you're buying multiple boxes, I'll probably use UPS; if in doubt, contact me.
6" x 2.25"
On porcelain, Earth crust slurry is brown glaze on the back. Interior is a copper red glaze assembled from refined materials. Copper volatilizes during firing and the areas of green and red show the air circulation that carried that copper through the kiln's chamber at high temperature.
4.25" x 3"
Top exterior is Earth crust slurry from Mid-Atlantic Ridge and bottom half is from Costa Rican subduction zone. Interior shiny whitish glaze assembled from refined materials.
12" x 1.75"
Center of sea-glass is surrounded by an area of chattered porcelain clay that was glazed with rock slurry from the Kane Fracture Zone, and area of the Mid-Atlantic Ridge. outside of that is fine-grained sediment from the Costa Rican accretionary prism, an area of subducting plates under immense pressure from friction.
4.5" wide x 2.75" high
Exterior chatter pattern is the Mid-Atlantic Ridge rock slurry also known as the Kane Fracture Zone. It also surrounds the sea-glass center. The speckled brown sediment glaze is from a subduction zone some people call the Costa Rican accretionary prism.
5.5" x 1.25"
The words describe dynamics at three sources of interior glaze. From center outward: Havre pumice-mud (erupting), Kane Fracture Zone (remagmatizing) and Costa Rican accrectionary prism (subducting). Click on back image to read the words.