I would have used high grade silicone adhesive such as Dow Corning 795,
probably with no fasteners.
If you want to fasten it with screws or nails, you will need to predrill
the terrazzo just like you would in concrete. With a masonry bit, drill
a lead hole, then drive the nail. Another related method would be to
drill and install plastic anchors or drill slightly oversize and insert
solder or copper wire in the hole, then use nail or screw. You will
know when you have a good fastener.
Keep the whole world singing. . .
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