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THE SCIENCE BEHIND THE BEAUTY

The ammonite’s pattern serves as a kind of living blueprint to its shell-housing architecture. Imagine a deserted curvilinear house with add-on rooms whose owner occupied each room as it was completed until finally settling in the last room. Of course, there is a practical scientific reason for all this expansion. Each chamber, or as many as needed, can be filled with gas to lift or lower the ammonite to a precise depth for feeding. No wonder the ammonite is prized as one of the earliest signs of intelligent life.

Once ammonites died and were buried in sediment, usually on ancient ocean floors, Mother Nature began to transform their shells into fossils, some of which are beautiful enough, when cut cross ways, to become art objects suitable for use as gems. Slowly, by a silica-immersion process, she broke down the ammonite’s calcium structure and replaced it with local minerals that both stained and solidified the shell. Think of Mother Nature as a kind of Andy Warhol, obsessively painting iconic logarithmic spirals the way Warhol did iconic Marilyn Monroe images, starting with the shell’s basic spiral design, then adding variation to each using different minerals for variety of color and texture.

Today, Madagascar is the biggest source of ammonite. Variety is so great from this cornucopia that there is no one peak of excellence for this fossil in gem slab form. My own favorites are pieces which exhibit remarkably opal-like iridescence, the result of micron-thick silica layering.
Russia is also a major provider of ammonite. We especially love its pyritized pieces where this particular iron sulfite has formed a kind of thick fool’s-gold leaf that make them look bathed in metal.

Morocco supplies ammonite with distinctive white and black, as well as black on black, spiral patterns that remind one of very elegant counter tops. Last but not least, Canada produces ammonites with the rich reddish-brown coloring of Madagascar plus areas of deep forest green.

At present, ammonite is used mostly for silver jewelry in pieces usually retailing for under $500. But Russell has made some extraordinary ammonite necklaces costing considerably more that could almost serve as breastplates. These remarkable pieces have a kind of ceremonial high-priestess look that suggests the archetypal pull of ammonite would have been present at any time when these art-relics were encountered.