Full Idea
The difference between skills and virtues is that virtues must be enacted, are always desirable, can't be forgotten, and can be simulated, whereas skills are very specific, involve a technique, lack contraries, and lack intrinsic value.
Gist of Idea
Eight marks distingush skills from virtues
Source
report of Linda Trinkaus Zagzebski (Virtues of the Mind [1996], II 2.4) by PG - Db (ideas)
Book Reference
Zagzebski,Linda: 'Virtues of the Mind' [CUP 1996], p.107
A Reaction
[my summary of her II 2.4 discussion of the differences] She observes that Aristotle made insufficient effort to distinguish the two. It may be obscure to say that virtues go 'deeper' than skills, but we all know what is meant. 'Skills serve virtues'.