Click to enlargeThe 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.



Pink and Green Flashing ~ Costa Rican Sediment
Pink and Green Flashing ~ Costa Rican Sediment

4.75" x 3.5"

Sediment, evenly dipped into slurry, contracted in kiln, exposing vitrified porcelain clay. Interior white glaze and exterior copper green assembled from refined materials. Turquoise sea-glass thumb-well.


Availability: Usually ships in 2-3 business days

FM-4US$65.00
Gritty Bumps, Wrinkles and Clear Colors
Gritty Bumps, Wrinkles and Clear Colors

4" x 3.25"

Sediment, evenly dipped into slurry, contracted in kiln, exposing vitrified porcelain clay. Interior white glaze overlaps sediment and gives more info about how materials influence each other. Exterior copper green assembled from refined materials. Blue sea-glass thumbwell.


Availability: Usually ships in 2-3 business days

FM-5US$65.00
Converging and Diverging Plate Boundaries on Porcelain
Converging and Diverging Plate Boundaries on Porcelain

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.


Availability: Usually ships in 2-3 business days

5-C44US$60.00
Costa Rican Accretionary Prism on Porcelain
Costa Rican Accretionary Prism on Porcelain

4" high x 2.75" wide

This sediment might be fine-particled because of being at a subduction zone where plates grind and pressure is immense. When these small particles are applied to clay as a slip, they shrink a lot and curl like a dried river bed when they melt back down and fuse onto the clay in the kiln.

Interior shiny white, top third exterior is a copper glaze assembled from refined materials.


Availability: Usually ships in 2-3 business days

FC-2US$70.00
Costa Rican Cup
Costa Rican Cup

4" x 3.5"

My interpretation of pressure at the Costa Rican subducting plates is that forces there ground the sediment into very fine particles that contract against the once-fired clay -- the shrinkage causes flakes to either fall off or peel back and then, during firing, they fuse onto the clay, leaving spaces. This tells that story. Interior shiny glaze assembled from refined materials.


Availability: Usually ships in 2-3 business days

C-507US$40.00
Costa Rican Subduction Cup
Costa Rican Subduction Cup

4" x 3"

Exterior glaze is the sediment. Interior shiny white assembled from refined materials.


Availability: Usually ships in 2-3 business days

C-512US$45.00
"Subduction Forces" Cup on Porcelain
"Subduction Forces" Cup on Porcelain

2.75" x 3"

Brown is the Costa Rican sediment glaze. Interior shiny white and other glazes assembled from refined materials.


Availability: Usually ships in 2-3 business days

CP-61US$45.00
Costa Rica and Copper Red/Green on Porcelain
Costa Rica and Copper Red/Green on Porcelain

4.25" high x 3.25" wide

Costa Rican sediment so fine grained that it curled as it dries (like a dry riverbed) and then again it curled in the kiln and contracts back down. Porcelain clay is exposed and vitrified. Interior white glaze assembled from refined materials overlaps a copper glaze on exterior , making red and green areas by how oxidizing or reducing atmosphere influenced it during firing.


Availability: Usually ships in 2-3 business days

FM-2US$60.00
Folding Fracturing Fissuring on porcelain
Folding Fracturing Fissuring on porcelain

5" x 3.25"

Subduction sediment evenly dipped on the lower exterior beaded up leaving all sorts of evidence, from smooth to gritty. Interior shiny white over a brush-load of matte green produced the teal-blue band. Sea-glass thumb-well.


Availability: Usually ships in 2-3 business days

FM-24US$200.00