In identifying iolite with Pliny's hyacinthos, I am admittedly going out on a limb. I have several specimens of iolite, which show a marked pleocrhoism or color change. Viewed along one axis, the stone is a deep blue violet, hence the name. Change the viewing angle and the stone turns to gray and then to a muddy yellow. Some historians believe this is the Vikings' sunstone, however that identity is by no means certain.
--[] 02:26, 7 May 2006 (EST)
Hi, nice articles, minor semantic point - you use the word "Ceylon", but that country has been called Sri Lanka since 1972. (and was not called Ceylon until the British collonised - well post medieval).http://en.wikipedia.org/wiki/Names_of_Sri_Lanka I hope this doesn't mean all your references are at least 34 years out of date! Tiff 23:25, 7 May 2006 (EST)