Usually Barium Sulfate scale with Uranium or Radium atoms substituted into the lattice structure. Can be detected downhole with a gamma ray log. Radioactive material occurring naturally in the environment including material brought to the surface during oil exploration and production. Usually Barium Sulfate scale with Uranium or Radium atoms substituted into the lattice structure. Can be detected downhole with a gamma ray log.

It can sublime, or go directly from a solid to a gas.

Considerable expansion may be caused along the "C" axis by water moving between silica layers of contiguous units (interlayer water absorption). Considerable expansion may be caused along the "C" axis by water moving between silica layers of contiguous units (interlayer water absorption).