Zircon and Zirconology - The Study of ZirconMost gemstones were formed millions of years ago in the Earth. Indeed, the mineral zircon is a special case. The oldest known zircon samples, from Western Australia, are more than 4.4 billion years old. blue-zircon-pink-zircon-golden-zircon-zirconology
Blue, Pink and Golden Zircon Gemstones
Zircon is actually the oldest known mineral on Earth. Considering that the Earth formed 4.56 billion years ago, the oldest zircon gemstones represent the earliest record of the Earth's crust. Zircon was the first crystal to form in molten granite as it cooled to form rock. The ancient granitic rock has long eroded away; the only record left is zircon in the form of tiny grains. This means that zircon is the oldest substance on Earth; the oldest samples are even older than the moon, which formed about 4 billion years ago.
Zircon also has very marked birefringence. Birefringence is a measurement for gemstones that are doubly refractive; that is, gems which have two different refractive indices. When a beam of light enters a doubly refractive gem, it is split into two beams, each travelling at a different speed and on a different path through the crystal. Birefringence is a measurement of the difference between the two refractive indices in such gems. Zircon has such high birefringence that a zircon gemstone may appear fuzzy or display 'facet-doubling' when it is viewed through the table. Special cutting skills are required to minimize these effects.
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In addition to its notable birefringence, zircon has a very high- Erstausgabe: January-28-2008
- Zuletzt geändert: January-24-2019
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