Flourite as a substrate for Corydoras catfish?

[Cheryl Trine <ctrine at andrews_edu>]

All the advice I have read about keeping Cory cats indicates that the
gravel substrate should be rounded so that they won't wear their barbels
down to nubs.  After I washed my flourite with bare hands, they felt
rather rough and scraped up, so I am wondering if this is an appropriate
substrate for a planted tank with cory catfish.

If flourite shouldn't be used, what would be a good alternative?  Could
I cover the flourite with about an inch of rounded gravel or sand?
Would this just get mixed when vacuuming the surface, and bring the
flourite to the top?

Thanks for any advice.

Cheri