OVERVIEW
The goal of this buyer’s guide is to leave you, the consumer, less confused for reading it, not more so, by providing useful, unbiased information that will aid you in understanding ammolite. It will be broken into categories, so you can read as little or as much as you like, and focus on your particular area of interest.
It also comes with a caution. Realize that everyone is trying to sell you a product, and of course, they want you to buy theirs. Be wary of anyone using scare tactics, or who gives you rules for buying. There are some self-proclaimed “experts” out there, stating opinions and half-truths as hard fact. Use your own common sense and objectivity. Question everything (including this guide).
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THE BASICS
The fundamental principle is that a gemstone must be intrinsically beautiful to have value. This is the reason people buy gems, and any retailer can tell you that a gemstone that cannot find an owner, is essentially worthless. Any cutter, who doesn’t understand this basic principle, is in the wrong business. The cutter’s job is to unlock and maximize the hidden beauty within the stone.
There are various ways for him to achieve that. Shape is everything! Color is everything! Finishing is everything! If a stone doesn’t come together to provide an overall perception of beauty, it has failed to realize its potential, and its value is low. It isn’t about what the cutter is or isn’t able to do. It’s the beauty of the finished piece that establishes its desirability and value.
ROUGH AMMOLITE
Rough ammolite is obtained either by surface picking the outcroppings where the gem bearing ground has been exposed by erosion, or by open pit mining. There are river systems which cut into the ancient bearpaw shale formation, which holds the ammonite fossils, and these are the source of the surface picked material. It takes many years for the rocks to weather out of the ground, through a process of repeated freezing and thawing, wind, rain, etc., and typically, they suffer significant decomposition in the process. Some are completely calcified (basically chalk) by the time they are exposed, but others survive in better shape. This is the source of most of the fossil specimens on the market today, but is, generally speaking, a poor source for gem material. The best gem rough is mined in deep open pit mines, at great expense. Thirty feet or more of overburden must be removed, before the ground becomes solid enough to begin mining for the ammolite gems. Then great care must be taken to hunt through the layers of shale to find the discreet ammolite bearing shells, as they are slowly extracted with the aid of heavy equipment.
NATURALS AND DOUBLETS
A natural stone is one that is cut and polished from one piece of rough ammolite. It can be solid gem (shell), or backed on the original matrix rock it was attached to (not re-backed). When considering quality, I have to emphasize shape. Avoid stones that lack flowing lines and balance, as they will be difficult to incorporate into a beautiful jewelry design. I take issue with those who say shape isn’t important. “Lumpy” edges, and clumsy shapes are signs of inferior cutting, and the minimal extra weight doesn’t add to the value of the stone, because it decreases its desirability. Finish is also very important. A good natural should be cut only from the most stable stone, or it will not polish. There should be no pits, scratches or other incongruities in the surface, but rather, an even, overall polish. Otherwise the material would be better off as a capped stone. We’ve found high pressure stabilization to be the most effective method to achieve a high polished natural, but unfortunately, only the mining companies have access to this expensive technology. Poorly polished stones have a low value, and would be better off priced by the piece, than by the carat. I would categorize them as “specimen grade”. Most surface collected material has some degree of decomposition and calcification, and so it is rarely gem quality. Our excavations have shown that even 50 feet or more back from the riverbank, material in the ground shows noticeable decomposition. The goods stones come from the mines (of which there are only two), and are dug from ground approximately fifty feet deep. If you are buying stones which are clean, bright and stable, chances are they came from one of the mines (one way or another).
Some “naturals” have been re-bonded to the matrix rock with epoxy or other glues, and these would be more correctly called doublets. They can be spotted by the facet flat plane where the layers are joined. These stones are commonly referred to as naturals or natural doublets , however, by gemological definition; a natural doublet is a stone which is naturally bonded to its matrix. Consequently, a re-backed stone is properly called a doublet (apologies to those whose feathers this may ruffle).
CAPPED STONES
Capped stones include doublets, triplets, and mosaic stones. When properly constructed and cared for, they provide a durable, long lasting gem which can endure the wear and tear of daily use, and withstand the test of time.
Several different materials are used for caps (or tops). Synthetic spinel is by far the best choice. This synthetic gem material has a hardness of 8 on the mohs hardness scale. Spinel capped triplets are superior to naturals for day to day wear, and when properly cared for, will last for many years. Quartz is also a durable gem material, and hard enough to wear well (hardness is 7), but it is more brittle than spinel, and easier to chip. Glass, or leaded glass (which goes by the trade name of crystal), is a soft material and prone to scratching, so I personally don’t recommend it.
Resin topped stones are the “fast food” of ammolite production, and should not be taken seriously as gemstones. They consist of epoxy glue, or similar resin materials coated on the ammolite, and are neither durable nor long lasting. They can make some beautiful gems however, and, provided the price is right, may be a suitable choice for your needs.
Quality of construction is very important to achieving a good, long lasting stone, and involves a series of steps too complex to effectively describe here. I suggest you trust the dealers who’ve been making the product for years, and have a good string of feedback to support them. If a cutter or seller tries to scare you away from capped stones, it may be that they aren’t very competent, themselves, at manufacturing them.
STABILIZATION
Ammolite is similar to mica in structure, in that it is composed of many layers of thin sheets. You could also think of it as pages in a book, bound together, yet easy to separate. Sometimes the layers are loosely bound, sometimes more tightly. This is especially true for surface picked material, which has suffered some decomposition in its years of working its way out of the ground, although, most of the stone we pull from the mine has similar properties. It comes out damp and fragile, and hardens as it dries. For this reason, its a stone that benefits greatly from some type of stabilization. Without that, it is prone to splintering and chipping.
For years, many hobby level, and small scale cutters have sworn by a product known as opticon fracture sealer. The working theory behind this product is that you soak a liquid resin into the gemstone, with the aid of heat, and cure it with a surface treatment of a hardener, which is supposed to create a chain reaction, hardening the resin throughout the stone. In my opinion, these claims are optimistic at best, as I don’t believe epoxies work that way. In fact, over the years, I have heard reports from dealers, who have found that under the showcase lights, in some cases, this liquid resin oozes back out of the stone, and these stones have acquired the unflattering name of “leakers”. This is not to say that the treatment is a problem in all cases, and it certainly helps the cutter to acquire a polished surface. But, in my opinion again, I think the process is overrated, and in this day and age, should go the way of the dinosaur. The resin is also toxic, and I can’t name one woman who would want it on her party dress.
These days, there are advanced, job specific epoxies available, which create a much more desirable result. In our factories, we use a sequence of pressure and vacuum treatments, which permeate the material in a more effective and permanent manner, and create stable gems with more predictability and consistency, and a potentially longer life span.
INCLUSIONS
I respectfully borrow a line from my gemology instructor… nature doesn’t create perfection, it creates excellence. This is the reality in the world of gemstones. In most colored stones and diamonds, inclusions are used as a means to separate the real stones from the fakes, and so, some degree of inclusions are in fact desireable, although the fewer the better. Inclusions can be solid, liquid or gas.
Ammolite, which has no effective imitations or synthetics, does have its own unique types of inclusions. Some are mineral, and some could be described as partial fractures. Mineral inclusions could include calcite, pyrite, the host rock in which the stone is found, or other minerals. Partial fractures occur when the gem layers are split, but still remain partially bonded on a molecular level (similar to a crack in a bone as opposed to a break). Both are responsible for some of the gliches seen in the finished stones. Some inclusions can be a combination of the two, mineral and fracture. Aside from this, you can also sometimes see a banding in the stones which is the result of cutting through the various shell layers. Some layers have a more creamy or smoky appearance than others. Some cutters have declared this effect to be taboo (because they find it next to impossible to polish through these layers without pitting or chipping… again, a stabilization issue), however some of the most beautiful gems are created this way, and I don’t share their views.
GRADING
Grading is a complex issue, and proper grading should be left to professionals. However, ammolite is a rare stone and many gemologists have little experience with it. Most, if not all the boasts of AAA grade are false, and should speak to the dealer’s credibility, so take the claims with a grain of salt. The basic levels of grading, for commercial purposes, are standard grade, A grade, A+ or AA grade, and AAA (or collector’s) grade. We manufacture thousands of stones per year, and almost never use the last designation, which should be reserved for nothing but the finest. Quality is determined by a combination of color and brilliance. Equal amounts of primary red, green and blue, with a high degree of brilliance are most prized and rare. In a truly top level stone a high degree of clarity should also be present (lack of inclusions). The most important factor in establishing the grade is color, but as in all gems, brilliance, clarity and cut also come into play.
The vast majority of stones I see listed are standard and A grade stones. Stones with pitted surfaces, poor color and/or cut, should be called B grade. Use your own discretion and common sense, when bidding or purchasing, and if it seems too good to be true, well….
LEGAL ISSUES
This is a touchy subject, and when approaching it, many ammolite “aficionados” become instantly defensive. But to quote another buyer’s guide – truth hurts – and – honesty is the best policy -.
Ammolite, and Alberta ammonites, have a dual status under the law, being considered both a fossil, and a mineral. They are considered cultural property by the Canadian government, and can only be collected under specific conditions. Ammolite, as a fossil gemstone, requires disposition from the Alberta government. This involves photographing the material, and submitting it with documentation for examination by the Tyrrell Museum of Paleontology, for assessment of its historic or cultural value. Much of what you will see has not undergone this process. The gem bearing ground is not accessible to the general public, and can only be collected on with the permission of the land owner, and claim holder. Neither of these parties is generally agreeable to public collection, yet unwelcome pickers are common.
The exception to this is native owned land, which natives can rightfully pick. However, some dealers use this as a means to circumvent the system. Although buying from the natives is legal, their sources can still be questionable.
Trespassers in the mines and on claims are an ongoing problem. The bottom line is, there are very few legal avenues to obtain ammolite.
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