Ammonite, Placenticeras costatum

Detection area: Alberta, Canada

Genus: Placenticeras costatum

Size: diameter 35.5

Age: 145-163 million years

Period: Jurassic

Weight: 77.5 kg

Brilliance: Excellent Iridescence

Detection year: 2017

The ammonite is a fossil of an ancient cephalopod mollusk, distinguished by its uniquely shaped shell. These fossils date back approximately 145 to 163 million years. Ammolite, a highly valuable gemstone of organic origin, includes other such gems as coral, pearl, jet, and amber. This rare gem is found on some ammonite fossils and is renowned for its scarcity and beauty.

 Ammolite is listed among the ten gemstones that are rarer than diamonds, highlighting its exceptional rarity and value.  The world's sole ammolite deposit is located in Alberta, Canada, making it a unique geological and cultural treasure. Only 5% of all ammolite finds meet the quality standards necessary for gemstone processing, underscoring its rarity and the skill required to work with it.

 A remarkable property of ammolite is its iridescence, which means it changes color when viewed from different angles, adding to its mystique and appeal.

Among its spectrum of colors, blue and purple are the most rare and sought after. These colors are the most challenging to preserve during the gemstone's processing, thereby increasing their value and desirability in the market.

 Ammolites are mined by open pit mining from the "Bear Paw '' geologic layer, which covers the area from the province of Alberta in Canada to Utah in the United States. The layer itself lies at a depth of 15 meters and is another 15 meters thick at the area of the Inner West Sea, which existed here about 100 million years ago. The ammolite content of the rock is negligibly small. Thus, in 1999, 165 thousand tons of oil shale was quarried and 21 kg of commercial-grade ammolite was extracted, i.e. only 0.64 carats per ton.  Mining requires a State license and surface restoration obligations, including the planting of native grasses.

The ammonite is embedded in the rock from the mine site. Coated with epoxy resin to anchor the fragile ammonite. Rainbow layer thickness 0.5-8mm before polishing and 0.1-3mm after polishing