Australian "Cowell" black Nephrite Jade Bangle - 59.25mm #2

Bangle Specifications:
Inner Diameter: 59.25 mm
Width: 15.85 mm
Weight: 61.6 grams

Grading Total: 9+

Grading Specifics

• Integrity:               9+
• Grain/Fiber:          9+
• Translucency:        2
• Color impact:       9
• Polish:                   9
• Workmanship:      9

GRADING DEFINITIONS - JADE
Integrity:  Ability to withstand impact. (Fractures, micro-fractures and brittleness)
Grain/Fiber:  Fine crystalline (Jadeite) or fine fiber (nephrite)
Translucency:  Light penetration into material from a light source
Color impact:  Expected color from material (There are different expectations from different jades from around the world and the jade source locations.)
Polish:  Ability to take a polish. Not all items are high polish but the ability to take a high polish shows a certain aspect in quality.
Workmanship:  Consistency of smoothness, edges, thickness and polish.

Grading Scale:

• 7 to 10: High     
• 4 to 6: Medium
• 1 to 3: Low

Cowell Jade History

Jade Deposits near Cowell on the Eyre Peninsula (South Australia) are among the largest nephrite jade deposits in the world. They were discovered in 1965 when Harry Schiller, a local farmer prospecting in the area, collected a 3-4 kg boulder of dense, hard rock near an outcrop of white, marble. The boulder was tested and identified by Adelaide University and the South Australian Museum.

91 separate jade outcrops were identified by the SA Department of Mines geologists in 1974, today well over 100 outcrops are known. All outcrops are located within an area referred to as the Cowell Jaded Province. All these sites occur on 23 leases held by Gemstones Australia Pty Ltd.

Technical information about the Cowell Jade product

The Jade bodies at Cowell typically have elongated, lensed shapes in outcrops. Host rocks are dolomitic marble and banded calc-silicate of the Palaeo to Mesoproterozioc Minbrie Genseiss, these high grade Jade deposits were form some 1840 million years ago.

Cowell Nephrite formed:

Within alteration zones as large boulders up to 40m long by 3m wide

Within cross-fractures up to 1m wide parallel to the axial plane during late-stage cross warping. Nephrite in cross-fractures is typically HIGH QUALITY, FINE GRAINED, MASSIVE AND DARK GREEN TO BLACK, but does occur in rare translucent light green colors

Withing irregular alteration of course-grained, brecciated diopside, producing schistose nephrite that has diopside inclusions

The geological setting at Cowell host rocks differs with other major occurrences of nephrite in New Zealand, Canada and Taiwan, where lenses occur within or along the faulted margins of serpentised ultramafic rocks such as peridots. With gives COWELL JADE, its fine grained and consistent dark rich green and black colors.

Cowell Jade exhibits a variety of colors and textures but consists mainly of medium to fine grained material greenish to solid black hues.

The 3 main varieties are marked:

Green Nephrite

Black Nephrite

Premium Black Nephrite

All products become a very high polish finish, with simple lapidary techniques, with the Very fine-grained premium black obtaining a mirror like polish.

I am adding additional information on the grading of each bangle. The purpose is to help educate all buyers and give people the appropriate information to better understand their purchase, and in the case of “high-end bangles,” their investment. This grading information is my personal attempt to inform others of the qualities of the material on a particular item. There are so many false jades, modified jade and simply inferior jade being passed off to uninformed buyers. I usually only work with high quality, untreated materials, but the materials do vary in quality even within the same stone so this will point out and identify everything about each bangle. When artists work on a piece of jade (in this case, a bangle), they get to personally know everything about the bangle. Many online sellers (including ETSY), are selling bangles made by production methods (CNC or many operators doing only one part of the process at a time), which also means a seller will have no personal knowledge of the item.

** Note: Many items stated to be "Jade" on Etsy and Ebay are not. In many cases, price does not indicate this either so buying an expensive item may be a jade replica like glass. There are many other stones including agate, grossular garnet, serpentine (many forms), aventurine... being sold as jade. To make it worse and more complicated, many jadeite stones are being reconditioned and died to be very attractive so they pass general tests to be real. If you see  very clear bangles, odds are they are agate, glass or something else. If you see very bright colors of red, yellow, purple... most likely not real. I say this as many buyers are being fooled on-line by these practices.