Vintage for sure. With certainty I can say it is at least 60 years old. But know it is much older.
4" wide at the widest point.
Could be some type of stone or salt? To touch it feels chalky. Image shows deterioation which occured before I got this piece from my grandmother over 50 years ago. Almost looks like wear from water coming in contact with it. The base has been glued to prevent further cracking, again this was in the condition it is when I got it 50 years ago. I have been carrying from house to house, state to state with no incidents.