Our regular column “Stone mascot of the month” features December nephrite – a well-known gem that is often used as ornamental material. Its colour varies from light grey to grass green; it can be yellow, blue and black. The name ‘nephrite’ comes from ‘lapis nephriticus’, which in turn is derived from the Greek ‘λίθος νεφριτικός’, which means 'kidney stone' and is the Latin and Greek variant of the Spanish 'piedra de ijada' (from which the names 'jade' and 'jadeite' originate). Accordingly, nephrite was once considered a talisman that gave protection against kidney stones. Nephrite and jadeite were considered the same mineral until 1863. They share a composition dominated by calcium silicate with added iron and calcium. "Jade" is the term that mineralogists consider acceptable to refer to both stones. Of the two, jadeite or "Chinese jade" is less common and more valued, although nephrite or "New Zealand jade" is also very popular as material suitable for carvings especially in China where jade minerals are rather expensive and especially revered.
Jadeite is harder and rarer than nephrite. Currently, Burma is the country that supplies 95% of the world's gem-quality jadeite.

Classification of academician Alexander Fersman treats jade as a semi-precious stone of the first category. However, many scientists consider it precious. In European countries and the USA, diamonds, rubies, sapphires, emeralds, opals, garnets and some other precious stones are much more popular than jadeite and jade. Jade is not so highly-valued in these regions, unlike in China, where this stone is considered the national one.

In the 18th century, after the trade agreement was signed between Burma (Myanmar, since 1989) and China, jadeite was flooded into China. The members of the imperial dynasty soon appreciated it. Chinese artisans always distinguished jadeite from nephrite, and paid more for jadeite. Nevertheless, in modern publications, despite the well-defined difference between nephrite and jadeite in terms of chemical composition, hardness, light refraction and price (jadeite is much more expensive) a certain confusion exists.
Jade was widely known and used in processed form as early as the Bronze Age*. At that time, it was considered the most durable stone, which was preferred for making weapons, tools, amulets and talismans and figurines of the gods. Some items are known to have been made during the Neolithic period.

The ancient Egyptian priests associated the mineral with magic and power on the earth and underworlds. In the Muslim East, nephrite was considered the stone of winner, used for inlaying weapons, in particular for making sturdy handles for daggers, and for decorating knives and shields. Later, nephrite was used to decorate clothing.
In China, there is a statue of Buddha, which reaches up to six meters in height and is made of precious white jade. There is a tombstone in Samarkand that covers the tomb of Tamerlane (Amir Timur) in the Gur-e-Amir Mausoleum. Its uniqueness is that it is made of dark green-coloured jade. This piece is considered to be the largest stone of such a rare colour in the world. Tamerlane's grandson Ulugbek brought the tombstone from China.
As it has already been noted, the Chinese practically did not use jadeite until the 18^th century. All ancient carved items in Celestial Empire were made of jadeite: famous spheres arranged one inside another, exquisite vases, bowls, goblets, caskets, figurines of animal and pagodas. Jade was very highly valued in China – it was used to make plaques that were as valuable as coins, and paired jade plates served as passports for imperial envoys. Other sacred objects were also made of jade. Academician Alexander Fersman called jade "the national stone of China". There it is deified, and its useful properties are equated with the best qualities of human character: courage, patience, compassion.

Nephrite is not always green, although it is the green mineral with the most uniform colour that is valued the most. Different deposits provide mankind with nephrite of whitish tone, grey with veins and coloured spots, homogeneously black, yellowish-brown and even blurred blue.

Nephrite is found on each of the five continents. In Russia, its deposits are located in the Urals. The largest foreign sources of extraction are China, New Zealand, Canada, Kazakhstan and the USA.

New thematic photo album "Nephrite – the stone mascot of November" is posted in the museum Photo Gallery.

On the cover: Cigarette case. Russian Empire, Saint Petersburg. Fabergé firm, Henrik Wigström workshop. 1904-1908

*The Bronze Age is an epoch in human history (XXXV / XXIII - XIII / XI centuries B.C.) distinguished based on archaeological data, characterized by the leading role of bronze products.