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I collected some crinoid columnals and a horn coral....weathered from the Devonian Keyser Formation limestone in Pennsylvania. As usual, preservation is not very good.

Blair County, Pennsyvlania USA From roadside rubble outside an area quarry in the Keyser/Tonoloway, which is known to have karst features OK, so this isn't a fossil, but it caught my eye while fossil hunting, and I learned something so thought I'd share. One side of this limestone slab has a ton of pebbles glued to it with some sort of mineral layer, with the rough look of partially dried up butterscotch pudding (that's a technical term, right?). I don't see any fossils in this slab. The limestone fizzes, the glue layer does not. Just guessing, it looks like maybe there was at least a crack if not a larger passageway, debris from the "ceiling" accumulated, and later the mineral glue was deposited to glue them in place. Part of me wonders if this might be from the anthropocene, with quarry blasting shaking bits from above and then the mineral glue came along.... or maybe all these pieces were placed loose in a heap, and then the mineral glue came along.... Anyway, is there a technical term for this rock type? While prepping this post, I started wondering if stalagmites are sedimentary rocks, and then found this pretty basic info which explains that sedimentary rocks are divided between clastic sedimentary and chemical sedimentary. I kinda knew that intuitively but never really thought about it or knew the terms. Beyond me sharing my Aha! moment on something so basic, does anyone have a more precise technical term for this slab? Any opinion if if this shows all natural processes (before I came along that is!)

Greetings from Central PA. I'm a total noob when it comes to fossil prep. Today I have a flattish piece, about 10" across and 1" thick. It from a large outcrop of wavy laminations that I believe are from a Keyser Formation stromatoporoid. It's pretty weathered and too hard to tell if pillars are present. So I'd like to try to grind/polish one edge. I have a good collection of metal and woodworking sanders and grinders available but nothing specifically designed for rocks. So my QUESTION IS.... is there a reasonable way to grind/polish the edge of this sample to look for stromatoporoid pillars? I'm just guessing that false negatives are common doing this sort of thing. so I thought I'd seek expert advice before I just make up some hatchet job only to get iffy results. Thanks