Played with cement just a little bit before it got cold outside.... and now I have a 70% finished mushroom hanging out in my kitchen....
First, create a plain (if lop-sided) mushroom from a lightweight cement recipe that you just happen to have the ingredients lying around:
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Begin attaching "reject" glass pieces around the edge with mortar:
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Fill in the rest with pieces of broken and leftover kitchen tiles (these were really fun to smash in to smaller pieces with a hammer ---- though next time I think I need to break them in to even smaller pieces):
NEXT UP: grout the cracks & seal the mushroom...... someday when I get tired of having a half-finished mushroom in the corner of my kitchen :)