Chris Hogg wrote:
[...]
The finer you crush rock, the more energy it takes and the more
expensive it gets. Making builder's sand that way would be very
expensive. Certainly, rock crushing to make roadstone or aggregates
for concrete generates some fine stuff, but not nearly enough for
the
building industry.
[...]

On a point of information, last time I had the builders in big-time,
in '88, at one point their suppliers did run out of ordinary sand,
and did send "artificial" sand from crushed rock. I, too, thought of
the cost, but at that stage it wasn't worryingly more expensive than
natural sand; though it doesn't sound a sustainable technique, I
agree. As always, perhaps it's a question of balancing transport
costs for any given location against production costs at a given
source.

--
Mike.