text: The first real collections of crystal models were produced by Romé de lIsle. He actually offered sets of small (ca 3 cm) models made of "terra cotta" in order to stimulate the sales of the expensive four-volume set of his book "Cristallographie'" (1783). The models were manufactured by his co-workers Arnould Carangeot, Lhermina and Swebach-Desfontaines, who produced numerous large sets (up to 448 models in each set). In order to exactly transfer interplanar angles from natural crystals to the terra cotta models, Carangeot invented and designed a prototype of a contact goniometer. This instrument, that proved to be an invaluable tool in geometric crystallography, enabled the measurement of interplanar angles with a precision of about half a degree.
  Teylers Museum in Haarlem has a complete set of these terracotta models that were bought in Paris (in 1785) by Martin van Marum, the first director of the museum. After over 200 years, this collection is still complete and in perfect condition at Teylers Museum.