Most rock can be crushed for road base.  The overburden should...

Most rock can be crushed for road base.  The overburden should mostly be suitable as crusher feed to produce road base.  rock for bitumen screenings requires fairly high hardness and is a bit more difficult to source.  Granite is generally suitable for both and I suspect that any fedspar would also be suitable for both.  Any rock crushed for bitumen screenings would have to be fresh or close to.  If the WA Main Roads are engaging in an upgrade to the highway past our dooe some of the "waste" rock should be saleable to a contractor experienced in producing road materials.  He should pay some thing for rock already in stockpile.  Don't expect too much (perhaps $5 a tonne) but it is something.  Also the quantity required at that site is probably less than what is available