Those remain the oldest rocks discovered near the surface in specific Northeast. While New York, Precambrian stone is detected principally in the Adirondack region in the northern sector of the land.
Explanation:
That Grenville Mountains produced while the Precambrian as North U.S smashed with an antique super-continent and that sandstone, shale, and limestone inserted earlier were compressed and forced up onto the edge of the early North American continent. The power of the collision metamorphosed the rocks: sandstone matured quartzite, gneiss, either schist; limestone matured marble, and shale enhanced gneiss and schist.
The unknown mineral has to have a smaller hardness number (meaning it’s softer). It’s hardness can be between 1-7. Some minerals it could be (and their hardness) are: quartz-7 orthoclase-6 apatite-5 fluorite-4 calcite-3 gypsum-2 talc-1
