Only young, violet-colored specimens should be collected for food, rather than those that have turned brownish; brownish specimens have number of potentially poisonous look-alikes that are not covered here. The common and poisonous
Mycena pura can be similar-looking when it is young and still violet. It differs in that the cap is smaller, the stem is whitish, and it smells and tastes strongly of radishes. A number of other inedible/toxic species of
Cortinarius and
Inocybe are purplish and superficially similar but do not match all the key characteristics.
See also
Laccaria laccata.