Gemology: J is for ...
Our tenth visit to our gemology guide brings us the gemstones beginning with J. Welcome to Jacinth, Jade, Jargoon, Jasper, Jourado Diamond, and Jet.
Jacinth
Jacinth is a reddish-orange translucent gemstone, ideal for faceting and frequently referred to an ancient literature and one of the foundation stones of the New Jerusalem. Jacinth was also one of the twelve gemstones used in the biblical breast plate of Aaron. The term Jacinth is not often used anymore. Instead gemologists and jewellers simply refer to it as orange or red quartz, though Jacinth sounds much more mysterious and romantic!
Jade (Jadeite/Nephrite)
Jade is actually two different minerals, Jadeite and Nephrite, that are very similar in appearance and feel. Both have been used for millennia. Pre-historic jade axes, weapons and tools have been found, as well as polished jade jewellery dating back over 5000 years. Jade is an incredibly hard substance that makes durable tools and sharp blades, yet it also lends itself to being carved and polished for decorative purposes.
We all know of jade as a green gemstone, but it also comes in shades of white, yellow, pink and grey. Of the two different forms, Jadeite is the most precious, being a richer colour and a more lustrous finish when polished. The most perfect specimens of Jadeite are known as Imperial Jade and can be more expensive than diamonds. Traditionally, only the Emperor of China could own Imperial Jade, but nowadays anyone who can afford it can buy it. Many other lustrous green gemstones are confused with jade and sold as such to unwitting buyers, but only nephrite and jadeite are true jade. Terms like Mexican Jade, Amazon Jade, Jasper Jade etc. are simply descriptive names given to jade-like stones of a similar appearance, but of a different mineral composition.
Jargoon
Ever heard of Jargoon? Also sometimes written Jargon or Jargounce, Jargoon is a variety of pale zircon quartz suitable for gemstone jewellery use. Usually translucent in shades of pale yellow or pale brown, if the colour was richer this gemstone could be considered Jacinth.
Jasper
Jasper is a form of Chalcedony; usually mottled or banded with brown/orange colours. It's been popular for centuries, and was considered quite valuable in biblical times, though it is very affordable now. Most jasper is polished en cabochon or carved into beads. Jasper has many descriptive names associated with it, which usually refer to the location it was found, or the colours and patterns within.
Jourado Diamond
Jourado Diamond is a misnomer, being the name given to white spinel when used as a diamond simulant. Not technically a gemstone variety, we've included it here as a side-note of interest in a google search ;)
Jet Jet is an organic mineral, similar to amber in origin, being the left-overs from prehistoric trees. While amber is formed from the resin of certain trees, jet is the woody material itself which has been immersed in water and buried in layers of rich organic sediment for millions of years. If the wood had not fallen into water first, the result would have been coal instead! Both coal and jet are black and initially very similar in appearance, but jet is more durable, highly polishable, and suitable for more decorative purposes. Jet that was originally immersed in salt water produces a harder mineral than jet from freshwater sources. The most famous variant of hard jet is Whitby Jet, found in Whitby, Yorkshire, England. Jet jewellery has been found dating as far back as the bronze age, and ancient Romans would collect and carve Whitby Jet to sell throughout Europe. Jet saw a huge resurgence in popularity when Queen Victoria took to wearing Jet jewellery in mourning following the death of her husband, Prince Albert, but jet jewellery has been referenced in poetry and literature for many centuries before that.
Next week: "Jewellery for a Job Interview" Stand out for all the right reasons at your next job interview with our job interview jewellery style guide.
