Hi Jamey
Your papers about coloring agate is really useful . I appreciate that.
My question is , how many percent of black chalcedony and red agrees in ancient time were from natural rock without any heating or acid treat. I have seen dark gray rocks from East and north east iran.one of my friends showed me rocks then he cut Small Stones from that rock. Some were light color and some deep dark which is favorite color now in Iran plus deep red.so can we say when stone hasn't been dark enough they used to do heating or another way to make it nice. I mean in ancient time.these two dark Stones are from that rock

My second question is how about agate beads with eyes in the middle. I am sure you know what isay. Those which Chinese collectors and some westerners love too much.. normally round with an eye in the middle. Are those have been also man made or all natural . In Iran we call them 3 skin. Means three layer of Stones with different colors in the middle. I was wondering to know if there is any human interference to make these kind of eye agates.
Best wishes
Ali