Less valuable than (and inferior to) mother-of-pearl, prior to 1912 only negligible amounts had been gathered there, but during WW1 it became a source of income for pealers. Trocus was taken along the Barrier Reef as far south as Lady Elliott Island. ‘Shellers’ operated out of Cairns, Townsville and Mackay, sailing to Thursday Island to trade their catch.
The industry grew, with all the shell being exported to Japan. During the 1920s over-harvesting occurred; limits had to be placed on taking of shell below a minimum size. The “greedy” Japanese came to dominate this fishing industry. Streaks of red or reddish-brown on the back of a pearl button indicates it originated from trochus.
Although the rise of plastic buttons greatly reduced the market for pearl buttons, the industry continues. Trochus is still sold to button makers.