I would say it is quartz with a couple spots of galena (a form of lead ore). I would guess that the tent is from leached oxidized iron (rust) that was in or nearby the host rock. If the galena is at the right angle it will give off a gold or rainbow reflection. All that is deducted from my prospecting experiences.
As mentioned previously you may want to post your find in the Indian artifacts forum. It looks like an arrowhead. Those boys back east are sure to help you with it.
I'v been prospering for gold at least 30 years and that's what would be called dirty quartz. The OP'er wants to know what mineral it is not if it is an arrowhead, that part is obvious.