Also, how is tabby made?
Tabby is a type of concrete made by burning oyster shells to create lime, then mixing it with water, sand, ash and broken oyster shells. Tabby was used by early Spanish settlers in present-day North Carolina and Florida, then by English colonists primarily in coastal South Carolina and Georgia.
Subsequently, one may also ask, how do you make concrete seashells?
Heat your shells or other cement items (see step 1) for 4-7 hours, or until they start to become brittle and start to crumble in to sand like dust. To help make your shells or other cement into a more consistent sand, stir it every 30 minutes by mixing the shells (just like cooking).
The oyster creates its own environment by secreting a shell composed or ninety-five percent (95%) of calcium carbonate. The remainder of the shell is made up of organic material and trace amounts of manganese, iron, aluminum, sulfate and magnesium.