alexandrite

[Bobby]

Hi. this alexandrite has inclusions and the color change is like green to purple.is it supposed to be red and do inclusions bring down its value.

[arglthesheep]

I am not sure, if this is a question or a statement
For sure Inclusions and not the best colorchange will bring down the value for an Alexandrite.

[Barbra Voltaire, FGG]

The GIA tends to be rather "Loosey Goosey" on it definition of alexandrite's color change parameters.
They will often call any shade of chrysoberyl with a color change alexandrite. Even if the color looks like squashed bug juice.

That being said, I think the stone you posted pictures of can correctly be referred to as alexandrite. The inclusion scene lowers its value somewhat.

[Bobby]

Thank you.i have a few other srilankan alexandrites but they dont fluorescence in uv light .This one does.do srilankan alexandrites have flouresence .

[Bobby]

These are some pictures

[Barbra Voltaire, FGG]

In order for minerals to exhibit a color change or shift, it is my understanding that they most contain both chromium and vanadium.
But fluorescence in itself doesn't reveal much.

[chrisP]

Basically, the color change of gemstones is determined by standardized light. Laboratories normally use daylight lamps and incandescent light with certain standardized wavelengths to determine a colour change and its intensity.

[Barbra Voltaire, FGG]

Gemstones which do not contain a combination of vanadium and chromium as chromophores will not display a color change when exposed to varying Kelvin (a unit of measurement for energy) temperatures of light.

The exception is metamerism, often seen in the clothing industry, where fabrics which matched in color when being manufactured do not match in the stores selling them. This results from different K temperatures used in the relative facilities.

Metamerism test: - if you check the color of your skin in daylight and then again by candlelight, it will appear slightly different. We do not have color changing skin.

[Bobby]

Thank you for your reply.I had read that iron content supresses the flouresence and dulls the color change.Srilankan stones usually have high iron.This one must be just different but have still requested GIA to have a look at the stones again .Srilankans also seem to have a brownish color change and the clarity levels are also high.