Posts 1 and 3 are massive quartz with inclusions of mica. Post 2 appears to be massive quartz and mica as well however the faceting, or possible fracture lend me to think there may be feldspar in the mix. Post 4 appears to be a weather eroded bit of hard sandstone or granite. Posts 1, 3 and 4 are all weathered material. My thoughts.
Talking about rocks and showing off minerals are what goes on in this part of the forum. Enjoy and Welcome.