Can you please identify this mineral?

probably quartz

but it coudl be lots of other things too

Martian geology is slightly different than earth's geology and other minerals may be more common there

It may be quartz but there is a good chance that it may not be. Remember this is a picture from a mineral on Mars which is, as of March 03, 2012, 62.6 million miles from Earth (because of the elliptical orbits of Earth and Mars, the distance between the two planets are always changing).

However Earth and Mars are both rocky, relatively the same size and shape, contain water (though mars has only trace amounts), they both have atmospheres, are relatively close to the sun so there are similarities that may lead to similar or identical minerals.

I don't think they have identified free quartz on Mars. If they had, that would be extraordinary. It's more likely gypsum (something they have found on Mars).

Is it a piece of melted metal from the lander ?

The rocket motors shed small bits of aluminum.

see this article :

http://dadslifereviewed.com/metal-on-mars-found-by...