Jade Fractures

March 8, 2015By
Natural fractures in jadeite jade boulder have dark green or brownish lines caused by oxidation

Natural fractures in jadeite jade boulder have dark green or brownish lines caused by oxidation

Dear Arthur

Does a Jadeite Gemological Institute or Lab put in their gems report if they find cracks on a gemstone or jade?

The reason I asked is because recently at Jade shop, I intended to buy a Jadeite (Type A) “Guan Yin” carving figurine.

Upon checking I found a crack from the base of this Guan Yin Jadeite carving figure. I was told by the Jade shop owner that this was a natural crack on the stone, and if this was sent to a gem lab for testing and verification this crack would not be reported in the certificate of identification.

Visually, the crack was very obvious. This could be due to ‘natural crack’ or cause by dropping it.

Henry

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Hi Henry

Cracks on a gemstone may or may not be reported in a gem lab report. Unless the crack or fracture is so severe that it affects the durability of the gemstone, most probably, the gem lab report may just describe the presence of inclusions.

Most jadeite jade boulders destined for carvings have natural cracks. Natural cracks found in jade boulders are the main cause of color because trace elements like Cr3+, Fe3+ and Mn can find its way into the porous capillaries of the boulder, or oxidation can occur within the fractures of the jade.    

A dexterous master artisan will carve away the cracks, but if a crack is too deep a carver may utilize the crack line to form some patterns or motifs to enhance the beauty and outward appearance of the sculpture.

guan yin 1

A jadeite jade gem lab report normally does not report the presence of cracks or fractures.  Hence, even if you send the Guan Yin jade figurines to a gem lab, it is unlikely that this will be reported in the jade identification certificate.

How do we determine whether a crack line within a jadeite jade carving is natural or the crack line is recent and caused by mishandling?

Fractures within a gemstone or jade boulder can give some vital information as to the identity of the stone. ‘Natural cracks’ are fractures caused during the formation or crystallization of the boulder due to severe climatic changes, earth’s tectonic plates movement, earthquakes, gaseous content in the atmosphere and other geological factors. These types of fractures may have occurred millions of years ago.

When the cracks are annealed (when a gemstone is heated to a high temperature and made to cool slowly) over a period of time, the crack line will be oxidized and thus one can find such crack lines to be dark green or reddish due to the presence of iron.

Granular and sugary appearance of fractures on a jadeite jade surface

Granular and sugary appearance of fractures on a jadeite jade surface

However, if the fracture of a jade piece is recent, the surface crack will be granular or sugary in appearance.  (Note: The fracture of a piece of glass  is conchoidal, which is a distinguishing factor of molten glass)

Conchoidal fracture surface of glass

Conchoidal fracture surface of glass

Examine the crack at the base of the Guan Yin figurine carefully and you can determine whether the crack is ‘natural’ or is it a recent crack or chipping.

Arthur

 

Photo credit: Gemologyonline.com & Imgkid.com

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About the Author ()

I am a Graduate Gemologist trained at GIA in New York. I hold an MBA from Cranfield University, United Kingdom and a Bachelor degree in Mathematics. My earlier profession was a banker until I found jade in Myanmar in the early 90s. I have traveled to the fabled Hpakan Jade mines and Mogok in upper Burma with my second son. Three of my children were also Graduate Gemologist, GIA and they are deal in diamonds.

Comments (2)

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  1. Arthur says:

    If the crack is only a surface crack you have ask a jade cutter to grind that spot and polished it back.

  2. Henry Koh says:

    Hi Mr. Arthur,

    I am fully aware and know that Jadeite Raw stone will have so called natural cracks and that is acceptable. But as I mentioned of this jadeite guan yin figurine which I found the crack from the figurine after unseated it fromit wood base. The crack line is zig-zag crack on the figurine bottom base right up to the figurine feet to the skirt curve. If you observed carefully from my pic you can the crack from the figurine feet up to inbetween the skirt and the crack is quite deep and quite wide. So I suspected the crack is caused by dropping accidently and not natura cracks. Also you can see from your photos of your Jadeite raw stone the nature hairlines ceracks are not like zig-zags cracks.
    Thank you.

    Regrads,
    Henry Koh