@Pmcgc84 Lots of good recommendations, id like to throw this into the mix
Glass and steel have got alot of the same properties. Theyr hard, dense and hold their temperature (hot or cold).
Glass is cheaper and lighter than steel. Its often a good way to see if you might like to try metal toys without shelling out one as the metal is much more expensive. Glass is also lovely in its own right though and fun to try, just make sure not to drop it in the sink 