Venezuela 20 Bolivares #81 or #81a

I added in my collection a new coin, which like it's say in the title it's a 20 Bolivares VEN from 2002, but I don't know the km number,I don't have a coins scale so I can't verify the weight. Can anyone help me, how to make difference between nickel clad steel and aluminum zinc?

I will post some pictures, if needed.

Thanks,

Couple of ways that I can think of:

> Appearance - Nickel should be more shiny & polished looking while Aluminium & Zinc will appear more dull & flat

> Magnetism - Steel, whether it is clad in Nickel or not, should be attracted to a magnet while Aluminium & Zinc are both non-magnetic

I test it already with a magnet and is not attracted by the magnet. On the other side it's shinny. Probalby it's aluminum. I don't know.

Thanks,
Andrei