Diatomite, tripolite, novaculite, novaculit' or kieselguhr refers to mineral deposits of fossiled diatom. According to http://www.mindat.org/ Tripolite is not classified as a mineral.
It is also found in Tripoli, Libya.
Diatomite. Statistics and Information
Tripolite: Tripolite mineral data Citat: "...A diatomaceous earth consisting of opaline silica..."
The Lough Neagh & Lower Bann Advisory Committees: Diatomite Citat: "...Diatomite, or Bann clay as it is known locally..."
DIATOMITE - Definition by HyperDictionary.com