Thank you for your reply (655). But it seems to me that a commodity
which is not exchanged cannot be used (at least within the terms of
the economic system); the (concrete) labor done in producing it does
not function as social labor. If a worker produces a shirt that can't
be sold and is simply thrown away, the worker's labor turned out not
to be part of social labor; it was not "socially necessary." This
holds for coins as for other commodities.
Paul M.