What Exactly is the Gemstone Known as Jade?

Jade has been used in China for over 2,000 years. In the pre-Columbian Americas, jade was considered more desirable than gold. Jade has also been important in Maori tradition.

Throughout the ages and across cultures, we have come to know this green stone with a greasy luster as "jade".

And yet there is no single gemstone called jade. For a great portion of human civilization, it would seem, we have been laboring under a misapprehension.

That is, in 1863 it was discovered that jade was actually two separate gemstones - jadeite and nephrite.

It is reasonable to assume that the two gemstones were confused because of their immediately observable characteristics of being green and greasy-of-luster.

With the advent of the Age of Enlightenment, when scientific reason was championed, only then did other, non-visible, traits of the two stones become scientifically verified.

Jadeite and nephrite have different hardness's on the Mohs scale. Jadeite has a hardness similar to quartz (7 Mohs) while nephrite is slightly softer (6.5 Mohs). They also have different specific gravities and refractive indices.

While nephrite is mostly green, jadeite may have greater variations in colour including a mutton-fat hue, a lavender hue and an emerald hue.

For these reasons, and due to its rarity, jadeite is the more expensive.

If the two gemstones are different, why should do we refer to both as "jade"? Perhaps it is only for the sake of convenience that we persist with this inaccurate nomenclature.

Conversely, jadeite and nephrite share the same etymology. That is, they mean loin-stone - Jadeite deriving from the Spanish and nephrite deriving from the Latin.

We could speculate that our failure to disambiguate jadeite from nephrite, encourages unscrupulous traders to pass off other green stones as jade.

If nephrite and jadeite may both be called "jade" on account of their greeness, then why not other stones?

Indeed, some traders do try to sell other green stones as jade. Lesser-valued stones such as serpentine and soapstone have been passed-off as jade.

Valuable stones may also be confused as jade - amazonite, for instance.

The inclusiveness of other green stones as "jade" has cultural implications too. While in the West we limit ourselves to nephrite and jadeite as "jades", the Chinese do consider soapstone and serpentine (and others) to be jade.

This creates confusion in the trade industry. What may be valuable or desirable as "jade" in Chinese culture may not necessarily have equivalent worth to a Westerner.

Though the term Jade is inaccurate and potentially confusing; it is a happy misnomer that we have maintained for milennia. Reclassification is not necessary; rather education and instruction that jade refers to two separate stones shall suffice.