The type specimen was collected from the Darling Plateau in the Brookton Highway Nature Reserve in Western Australia at an altitude of 285 m (935 ft), where, in Eucalyptus woodland, it was found growing on a sheltered laterite ledge.

[2] Chrysothrix occidentalis has a powdery, crust-like appearance that ranges in colour from bright yellow to yellow-green or yellow-orange.

These colonies consist of tiny granular structures called soredia, which are fine and round in shape, measuring between 20–80 μm in width.

It typically grows on protected granite or laterite ledges within open Eucalyptus forests, ranging in altitudes between 100 and 650 m (330 and 2,130 ft).

Some lichens species frequently found alongside Chrysothrix occidentalis include Buellia substellulans, Lecanora farinacea, Ramboldia petraeoides, Xanthoparmelia antleriformis, and X. tasmanica.