The first occidental historical reference about the jade stone, is noted in the medical work, written in 1565 by the doctor Sevillano Nicolas Monardes, who indicated the “ijada stone” as a remedy for pains of the lower abdomen

In 1598 it was found in Italian language in the diccionary of Florio as “iada” and the French changed it into “lejade”, -le jade- and so the word was transmitted in the other modern languages.

At about the 16th century it was known as Nefritica Stone (relating to the kidneys) in Europe. From there comes probably the word Nefrita, under which one of the three jade varieties is known.

Scale of Mohs

It was the Austrian Friedrich Mohs (1773/1839), who proposed the hardness concept to determine the resistence of the minerals and precious gems. 

The 1st degree applies to soft minerals like the talc;

The 2nd degree applies to minerals, which can be scratched with the fingernail, such as the sulphur and the plaster.

The minerals of degree 3 can be scratched with a copper coin, for example silver, gold and serpentina.

Degree 4 can be scratched with glass, for example and malachite and obsidiana

Degree 5 can be scratched with a knife, for example turquoise or lazulite

Degree 6 can be scratched with a steel file, for example opal and quarz.

The stones with a degree of more than 7 can only be scratched with diamond instruments.

Chemistry of the Jade

The human beeings have managed to combine artificially through laboratory tests, various chemical elements to creat precious syntethic stones, so that we can find syntethic diamonds, rubies, sapphires, acuamarines, aquamarines, topazes and emeralds. But the jade could resist sience and still it hasn’t been possible to create stones in the laboratory, which imitate the jade.     

The Jadite is insoluble in acids and in fire it throws a orange-yellow flame. It belongs to the mineral family of the Piroxenes, its cristal system is monoclinical and it leaves a white line.

The jade stones have an average hardness of degree 7 and they have the same breaking resistance as steel, which allows to being cut with a permanent shine.