What makes white diamonds white?

[thecat]

I was browsing a colored diamond site when I saw white diamonds. I clicked on it thinking it means colorless diamonds till I saw opaque diamonds. Then I realised they have another tab for colorless diamonds. So apparently white and colorless diamonds are different. I'm fascinated by what makes white diamonds white? But some of their white diamonds look colorless to me. So what's the difference?

 

[John P]

Fancy white and fancy black diamonds typically derive their appearance from inclusions.

Most black diamonds are actually anywhere from colorless to dark brown, with such heavy clusters of dark inclusions that light can barely get through the stone. Some black diamonds may have a spectacularly high saturation of deep brown, green, etc., and appear black face-up (in such cases, strong backlighting under a microscope can reveal the tone). Pursuant to this, it's possible to irradiate dark diamonds to cause them to become blackened.

White diamonds also derive their appearance from abundant tiny inclusions throughout the crystal. In the most attractive cases these inclusions diffract and scatter light, causing opalescence. In other cases the haze of inclusions is not so diffractive, and the diamond appears more milky than opalescent.

 

[denverappraiser]

Fancy white and fancy black diamonds typically derive their appearance from inclusions.

Most black diamonds are actually anywhere from colorless to dark brown, with such heavy clusters of dark inclusions that light can barely get through the stone. Some black diamonds may have a spectacularly high saturation of deep brown, green, etc., and appear black face-up (in such cases, strong backlighting under a microscope can reveal the tone). Pursuant to this, it's possible to irradiate dark diamonds to cause them to become blackened.

White diamonds also derive their appearance from abundant tiny inclusions throughout the crystal. In the most attractive cases these inclusions diffract and scatter light, causing opalescence. In other cases the haze of inclusions is not so diffractive, and the diamond appears more milky than opalescent.

Is that the same as a 'cloud not shown'?

 

[John P]

Is that the same as a 'cloud not shown'?

In fact, I suppose the comments could say "COLOR grade based on clouds not shown"

 

[thecat]

Fancy white and fancy black diamonds typically derive their appearance from inclusions.

Most black diamonds are actually anywhere from colorless to dark brown, with such heavy clusters of dark inclusions that light can barely get through the stone. Some black diamonds may have a spectacularly high saturation of deep brown, green, etc., and appear black face-up (in such cases, strong backlighting under a microscope can reveal the tone). Pursuant to this, it's possible to irradiate dark diamonds to cause them to become blackened.

White diamonds also derive their appearance from abundant tiny inclusions throughout the crystal. In the most attractive cases these inclusions diffract and scatter light, causing opalescence. In other cases the haze of inclusions is not so diffractive, and the diamond appears more milky than opalescent.

Thanks for the informative post, John

 

[thecat]

[Is that the same as a 'cloud not shown'?

So this is the reason for avoiding diamonds with the clarity grade based on clouds not shown comment. Thank you, Neil.

Is that the same as a 'cloud not shown'?

In fact, I suppose the comments could say "COLOR grade based on clouds not shown"

 

[yssie]

Is that the same as a 'cloud not shown'?

In fact, I suppose the comments could say "COLOR grade based on clouds not shown"

Like.
Where's the button?