The Nazko perlite occurrence was found, in 1994, during a cursory examination of large rhyolite outcrops and an adjacent bank of glacial outwash exposed in a cut on the road from Quesnel to Nazko.

While no bedrock outcrops containing volcanic glass are known in the area, abundant clasts of perlitic rock can be found throughout the outwash deposit. The large size of many of the perlite boulders (50 centimetres in diameter), low physical strength of the rock and proximity to a large exposure of Eocene rhyolites (Rouse and Mathews, 1988; Tipper, 1961), points to a nearby source, most probably associated with the adjacent rhyolite outcrops.

The perlite rock is black to dark green, with microfractures resulting in platy, rod-like and isometric fragments. Four distinct types of volcanic glass were collected for expansion tests.

A sample of each of the four types was crushed to less than 1-centimetre size fragments, which were then placed under a propane torch flame for about 1 minute. All types expanded, increasing the volume of individual particles from approximately two to four times their original size.

The significance of this perlite occurrence is that it is the logistically best-located and accessible site in the British Columbia interior, and the authors (Hora and Hancock) believe that prospecting will locate the bedrock source of perlite rock in nearby Eocene rocks.

According to Peter Read (personal information, 1997) the bedrock source has been found nearby.