I’d be curious to know what particular location in Nova Scotia the
agate which you describe came from.
I’ve been collecting Nova Scotia agate for over 20 years, and
cutting it primarily into one-of-a-kind, designer stones. You can see
some of my work at Carol Bova’s site <www.bovagems.com>, click on
"showcase" and then on the “Hans Durstling Gallery”. Perhaps one of
the stones depicted there may resemble the one you describe.
One p[ossibility is that the chatoyancy of your stone may be due to
a zone of included fibrous zeolite mineral. Some of the thompsonite
from Cape d’Or for example will cut a chatoyant stone, and it is also
occasionally stained green by copper.
On the other hand you may be seeing the iris-agate effect, a silky
sort of chatoyancy which you see best when the agate is sliced very
thin and which can be accompanied by color banding. I’ve collected
some nice iris-agate from Scots Bay on the Blomidon peninsula in the
past, but this location is so accessible (you just drive right to
within 50 feel of the gravel beach), and so well known, that there’s
not a whole lot to be found there anymore.
Any chance of seeing a jpeg of your stone?
Cheers, Hans Durstling Moncton, Canada