How can one tell the difference?

[Kerrigan]

How can I tell if the Minilites on my Z are alloy or magnesium?

They are marked 14 x 6 1/2 x 13 and also marked 6-76 SM.

[zbloke]

Weigh them against a similar size wheel that you know is alloy, if yours are magnesium they will be much lighter

[franky]

if you've a spare set fire to it, if you can't put it out they're magnesium

[Ian Patmore]

If they are not painted (e.g bare metal/polished) they will be alloy, as bare magnesium reacts with the air/moisture and will oxidise....just polished the bare magnesuim rim on my wheels (again)....

[Kerrigan]

Sent photos to the American distributor for Minilite. He says after examining them they are most likely the alloy version of the mag wheels so not a problem.