How to select and evaluate jadeite – Part 2

Top Class Jade

Top Class Jade

Enhancement is an artificial way to improve the appearance of jadeite. Enhancement is able to advance the selling price of jadeite but not the real value. To unveil the secretes of enhancement can lock you on the real value of the jadeite. Due to the degree of treatment jadeite can be classified as following types:

  1. Type A (Allowing): No treatment is allowed except for surface waxing.
    The surface waxing is serving for the purpose to make the appearance more smooth and improve its higher reflecting capability. Allowing jadeite preserves the authentic quality to the most. Therefore you shall experience all the virtues of the nature of jadeite. Even under the daylight with your unaided eyes, you shall feel its fine texture, pure and soft color, and clear and distinct striking echo, etc.
  2. Type B (Bleached and Polymer impregnated Jadeite):
    Type B treatment involves 2 steps:

    • Bleaching. A promising but stained piece of jadeite is exposed to chemical bleaches and/or acids
    • Polymer-Impregnating. The jadeite will be further impregnated with a clear polymer resin, sometime even with green pigment.  This results in a significant improvement of transparency and colour of the material.
    • So far, type B treatment is only found in green or white jadeite not other jadeite or nephrite. Currently, infrared spectroscopy is the most accurate test for the detection of polymer in jadeite.

      There are few ways to tell Type B from A:

    • Type B will dress in nice color at first sight. While with further scrutiny, you will find the color is not thick and pure enough. Observing under strong light , comparing to daylight, the color and transparency will weaken.
    • The luster will diminish in 2 years. Thanks to the effect of strong acid, more cracks will climb on the jadeite gradually. The ugliness is inevitable.
    • The density is different from Type A. The striking sound and echo shows less clear and crispy than Type A.
  3. Type C: Coating jadeite
    Coating low level white jade with a layer of thin green membrane to turn the white jade into emerald green jadeite, is the so-called Coating jadeite. Actually, it is not a new trick, this deception has been applied to all kinds of precious stone.Fortunately Type C falls into the following drawbacks, which can help you distinguish its real identity.  The color is more artificial not pure and natural.

    Observing under strong light, you will find the color is not naturally distributed.  Observing with  Chelsea color filter, you shall find green color turn into red or colorless.  In some cases, even some strong detergent can wash the cover color away.

  4. Type D:Dyeing Jadeite
    Type D treatment is using special equipments to heat and dye a whole stone in order to fake the appearance of jadeite.  Type D shall be quit easy to tell apart from the rest. Following the methods I mentioned above, Type D is the worst fabrication.

    Jade Material

    Jade Material

Submit a Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>