Show the luster of opal many gems often without any apparent cause suddenly become crak ed or seamed the damage being be yond repair opals known as the un luckiest stones are so sensitive that their beauty Is frequently destroyed by their wearer s proximity to an open fire the luster 0 this stone s caus ed by the presence ot myriads of little fissures which deflect the light into the characteristic crisma ic color of the gem the tiniest ol 01 these fissures Is likely at any moment to destroy the stone |