When buying ammolite gemstones always keep in mind to buy from one of the suppliers who properly grades there stones in accordance to the industry standard. Guidelines on grading and pricing is well written and easy to understand in the "Ammolite 2" book by Donna Barnson A.GA. C.I.G.
Caution: Beware of buying from sellers who have created there own grading system for example the industry standard does not have a AAA grade and also the term Collectors Grade has been over used.
If you are interested in investing in Ammolite you may want to buy the "Ammolite 2" book. We sell them in our ebay store and will put some up for auction. It's a great investment so have fun but be wise.