I've put this photo up before, it's from Richmond gaol. (So why am I posting it again? Because I can.)

According to me, these were found in the courtyard during an archaeological dig. The gaol was built 1828, the two wings added 1835 and the place closed in 1928, so marbles from each end of that 80 year period? And what are they made of?
According to me, these were found in the courtyard during an archaeological dig. The gaol was built 1828, the two wings added 1835 and the place closed in 1928, so marbles from each end of that 80 year period? And what are they made of?