A quartz vein containing pyrite and galena, occurs in phyllite of the Lardeau Group.

The showing was discovered in 1898 and some work was done on it in that year and 1899. The Lost Cup was Crown-granted in 1905 to H. N. Baird et al. The property was part of the Windflower Project in the mid 1980s; see Goldfinch (082KNW076) for details. In 1987, Granges Inc. collected 435 soil samples over the Reverted Crown grants: Lost Cup, Nina and Phyllis. Granges reported that 1022 metres of diamond drilling was completed on the Lost Cup in 1988. In 2016 and 2017, Explorex Resources Inc. completed programs of prospecting and rock and soil sampling on the area as the Silver Dollar property. In 2019, Mariner Resources Corp. completed a 624 line-kilometre airborne magnetic and radiometric survey on the area as the Silver Dollar property.