Greek would also be possible, which would put the writing no earlier than 500BC. To my eye it couldn't pass for the earlier Phoenician alphabet. When you're t

Greek would also be possible, which would put the writing no earlier than 500BC. To my eye it couldn't pass for the earlier Phoenician alphabet. When you're talking about a mine that was likely operated for centuries, it's also hard to say "everyone who worked here was a slave" or "everyone who worked here was a well-paid highly educated craftsman".