For the weight you specified, .47 ounce, it really couldn't be aluminum. For a token of that diameter, I'd expect a weight of around 4 grams or so if it was aluminum.
I agree with Sap it's most likely german silver. On the off-chance it could be silver, there is a fairly significant difference in specific gravity between german silver and silver (around 8.6 vs. 10.5 for pure silver) so that would be one way to be more sure about it. I'm not sure if the silver version of this token was pure silver, but even sterling silver (.925) and coin silver (.900) have SG of over 10.3.
A specific gravity measurement is very easy to do if you have a digital scale accurate to .01g. There are a lot of videos on YouTube which show you how to do it.
Member of SPMC, FCCB,
ANA and ANS.
My U.S. Classic Commemorative Complete Set:
https://www.NGCcoin.com/registry/co...sets/278741/My U.S. Fractional Note Set:
https://notes.www.collectors-societ...eSetID=34188