What kind of rock or gem is this??
Hi! I'm not really familiar with oil sands. In reading about them, it appears that sulphur can be a by-product of the deposits. Since you didn't mention a sulphur scent and the sample appears to relatively hard (sulphur has a hardness of 1.5-2.5), I suspect this might be a quartz variety. https://geology.com/minerals/sulfur.shtml
I suggest taking this to a local geologist for further identification.
What a find! Good eyes!!