Page:Theophrastus - History of Stones - Hill (1774).djvu/193

 LXXII. Many other Properties there alo are in thee Subtances which are eaily oberved. As that ome of the Stones before named are of o firm a Texture, that they are not ubject to Injuries, and are not to be cut by Intruments of Iron, but only by other Stones.

LXXIII. On the whole, there is a great Difference in the Texture of the larger Stones; as may be learnt from the different Manners in which they may be worked; ome may be cut, others engraved on, and haped, as before oberved, by the Turner's Intruments, as the Magnet Gem, a Stone of very