 In the late 19th century, actual chalk (generally calcium carbonate, also known as calcite or carbonate of lime) was often used in cue sports on the leather tips of cue sticks to better grip the cue ball, but players experimented with other powdery, abrasive substances, since chalk itself was abrasive, and over time damaged the game equipment.In 1892, the aforementioned straight rail billiards pro William Spinks was particularly impressed by a piece of natural chalk-like substance obtained in France, and presented it to Hoskins for analysis.Hoskins, having encountered such material before, was able to determine that it was volcanic ash (pumice), probably from Mount Etna, Sicily.