Joined: Wed Oct 22, 2008 5:00 am Posts: 344 Location: Finland
Wow, cool indeed
To be honest I didn't know type IIb can be colorless D.
Quote:
does NOT fluoresce with long or short wave UV
I'm curious about your observations. Basically you are saying phosphorescence didn't show up as fluorescence until source was switched off. Was it perhaps masked by slight visible glow from the UV source?
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Apparently when the quantity of boron in a type IIb is minimal, a colorless diamond can be produced. Most IIb diamonds are blue or blue/gray :like the Hope Diamond which phosporesces red.
And, the lack of fluorescence is something that astounded me as well. It is not only our opinion, but the GIA called it : fluorescence:inert
Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
Way cool. Also didn't know that they could be D color. On another note, how many diamonds do this? I doubt very few are put under swulv for any length of time over a second or two, if at all. Anything that would tip you off?
_________________ I love the smell of Methylene Iodide in the morning...
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
We tested for phosphorescence after learning the diamond was Type IIb. Typical characteristics of Type IIb are cross-hatched “tatami” strain pattern, transparent to short-wave UV, electrical conductivity AND blue or red phosphorescence. So, of course, we tested for everything.
Type IIb diamonds account for ~0.1% of gem diamonds and as I'm sure you all know, are usually a steely blue or gray due to boron atoms scattered within the crystal matrix. A colorless IIb is super rare, but not unheard of.
Although one can not conclusively determine origin of diamonds by type, Type IIb diamonds are less widely distributed than others; most come from India and the Cullinan (formerly Premier) mine in South Africa (King et al., 1998; G&G Summer 2009 "THE “TYPE” CLASSIFICATION SYSTEM OF DIAMONDS AND ITS IMPORTANCE IN GEMOLOGY").
We have some more photos of the diamond coming soon...some real good ones.
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