GJ207-OOO - Jade: Identification, Treatments and Value

Registration

Please see the "Upcoming Classes" tab for class offerings and registration information.

Course Description

As an appraiser you need to know that fake jade material started making its appearance, first in Hong Kong and then later at the Tucson and other gem shows in 2011. It’s marketed as “Canadian Jade” and looks similar to nephrite jade from British Columbia or jadeite jade, but its dyed quartzite that could be identified under magnification, plus using refractometer. Come to this lecture and workshop and learn how to screen for A jadeite jade (natural colour), B jade (impregnated with polymer) and C jade (dyed) using only UV lamp! You need to also know your limitations using standard instruments in testing jade and when piece of Jadeite or Nephrite Jade in question should be sent to gem laboratory for advanced testing with VIS-NIR and Infrared spectrometers.  This class will cover:

• Properties of  Jadeite and Nephrite Jade
• Varieties of jade by colour and transparency
• Canadian Jade – main source of world’s nephrite jade
• Separation of Jadeite Jade from Nephrite Jade
• Identification and Jade imitations with standard instruments
• Dying and impregnation of Jadeite Jade
• Use of spectroscopy and microscopy in detecting dyed jadeite jade
• Screening for Jade (A, B or C) with UV lamp
• Testing of Jade with advanced instruments at CGL-GRS Swiss Canadian gemlab
• Quality grading of Nephrite and Jadeite Jade
  - 4C: Colour, Cut, Clarity and Cracks
  - 2T : Transparency and Texture
  - V : Volume
• Providing information on Jade pricing and researching prices
• Assessing quality of carving and artwork
• Disclosure of treated and imitation jades on appraiser documents

Additional Information

• Samples of Jadeite and Nephrite Jades of different types and quality, as well as common Jade simulants like serpentine, dyed quartzite, glass, maw-sit-sit (mainly kosmochlor) and aventurine quartz will be tested;
• Participants should bring their hand held instruments: loupes, refractometers, filters, hand-held spectroscopes; and
• Each participant will receive Letter of Completion by CGL-GRS and handout material of the lecture.