Truscottite
The mineral truscottite was discovered at the Lebong Donok mine, Benkulen, Sumatra, by Hövig in 1914. He considered it to be a hydrated calcium silicate of composition CaO.2SiO2.1/2H2O. Later work by Grutterink suggested a different formula, 2(Ca,Mg)O.3SiO2.2H2O, the water content being reduced to 1-3 molecules after drying at 120°. Grutterink noted that the composition, general character, and optical properties indicated a similarity to gyrolite. Flint, McMurdie, and Wells concluded from X-ray powder photographs that the two species were identical, although they detected quartz as an impurity in the truscottite examined. All known specimens of truscottite come from the original locality, and no further investigations have been reported.