A common jelly fungus nationally but rarely recorded in the Outer Hebrides. The common name comes from calcium oxalate crystalline inclusions, which are opaque white, this helps separate it from other Exidia species. Found on dead wood as pulvinate fruit-bodies but often confluent forming masses. Best looked for in winter wet weather; in dryer seasons is shrivels almost to nothing.

References: 
Ellis, M.B. & Ellis, J.P. (1990). Fungi Without Gills (Hymenomycetes and Gasteromycetes).