This is an English salt dish, open salt or salt dip measuring .75 inches high by 1.5 inches square.

The clear pressed glass open salt has an 8 point recessed star bottom and beveled corners.

The salt dip or open salt was made in England between 1940-1960 and is in very good ++ used vintage condition with no chips or cracks, but some noemal scuffing and roughening from being used.

The versatile square salt cellar or salt dish is seen on page 144 of the guide 5000 Open Salts, A Collector's Guide by Heacock and Johnson and is their pattern number 2826.  

Open salts are having a second lives as ring dishes, sauce dishes or sorbet dishes.

I love reinventing uses for vintage!