Look on e-Bay for "mineral display stands" or "fossil display stand". I bought one for the office for $3 or thereabouts, and it does its job...
Not what I have, but it should also do the trick: Lot 3 Acrylic Easel Display Stand For Slabs or Fossils | eBay
If you want to splurge: Lot of 5 Iron Metal Display Stands ** 2.5" x 1.5" ** | eBay
For that money it's not worth the effort to make your own.