Jadeite jade is perhaps one of the most difficult gemstones to identify simply because there are a number of gemstones whose characteristics resemble that of jade and the abundance of imitations in the market. There are a few key gemological tests which when carried out properly can provide confirmation of its identity. There are also some 'quick-and dirty' negation tests which will tell you that a stone is definitely not jadeite but yet you cannot ascertain the specimen's identiy in the absence of certain confirmatory tests. This quick test may be useful when you are a buyer in the field armed with a loupe and your common sense.

The following tests are useful to take note:

Crystalline Structure:         Jadeite jade is a crystalline mineral and therefore feels cool to the touch. If you rub the specimen and it warms up fast chances are the stone is not even crystalline. Or you can place the specimen stone on your cheek as this is a good way to detect the coolness of the stone. Unorthodox method - but this test has saved many a buyer from being swindled by unscrupulous dealers trying to pass on plastics or high-tech green acryllics to the unwary buyers.

Specific Gravity:          This is the relative weight of jade as compared to an equal volume of water. The SG is 3.3 +/-0.1, which means jadeite is 3.3 times heavier than water. One can feel the weight of the stone by hefting it on the fingers. As nephrite jade has an SG of 2.9, an experienced jade dealer can differentiate the stone just by hefting it on the fingers or if it is a big boulder lifting it with his hands. It has been said by many jade dealers that somehow the 'vibration' of the stone will get into you if you do it for a sufficiently long period. The first exercise that a person who seriously wanted to learn the jade trade from a master is to heft a variety of stones. After about 6 months and a few thousand stones of varied sizes and types a beginner would be able to separate jadeite and other stones just by hefting. A more scientific approach would be using a hydrostatic balance to measure the SG.

Hardness:         On the Mohs Hardness scale each gemstones is classified in the order of hardness from 1 to 10. Diamond is the hardest in the mineral kingdom and has a relative value of 10. Jadeite's hardness is between 6.5 to 7. Using a quartz crystal (7 hardness) a jadeite stone would resist the scratch of a quartz. Hardness test is destructive and is only useful when one is buying rough.

Scratching a nephrite jade round bar with a quartz. Notice that the scratch line is visible.

Refractive Index:         When light travels from air to a gemstone of denser medium the ray of light would bend on entering the gemstone. A common occurrence would be when one observes a stick immersed in water which gives it the illusion that it is bend. By measuring the velocity of light in air to the velocity of light in the gemstone the RI can be obtained. RI is the single most important factor in the identification of gemstones as each gemstone has a definite RI or a fixed range of RI. For jadeite jade the RI is 1.66 spot. The RI is measured with the use of a Refractometer.

Microscopic Observations:         To best view a gemstone a gem micrcoscope of 60x is required. First view the specimen under reflected light to observe its surface polishing taking note of any chips or fractures. A jadeite stone has numerous minute indentations like moon crater no matter how fine is your polishing or how well you wax it. These are called dimples by jade dealers and is also one of the characteristics of jade surface. Next you can use the 'darkfield illumination' (light emitting from the side of a microscope with the black buffer plate to give contrast) where you can see the inclusions and the texture of the specimen very clearly. Typical inclusions in a jadeite stone may include fine microscopic hairs, 'clouds' natural colored vein lines and small shiny crystal reflections.

Spectroscopy:         Using a spectroscope, the light transmitted or reflected by a gemstone can be analyzed. Certain wavelength are absorbed due to the presence of trace elements like chromium in jadeite. A line at 437nm is diagnostic of jadeite while a sequence of lines from 630 to 690 is confirmative of a natural jadeite. This is by far the most reliable method in determining whether a jadeite is dyed or natural. Dyed jadeite has a broad band width within the said range.

Other Instruments:         Other instruments like a 10x loupe, a hand-held spectroscope, A UV light, dicroscope (not of much use), polariscope, chelsea filter, fiber optic light are of great help, These tests give observable, objective and repeatable results in a gem lab.