What colour are crystals (inclusion) generally speaking?

[haagen_dazs]

"Included Crystal inclusions are whole crystals or tiny included gem fragments of undigested crystals such as garnet, diopside, olivine, spinel, calcite, iron oxides, silica or other gem stone inclusions."

In your daily purview of diamond stones, what is the most common colour of crystals (inclusions) ?

If that is too vague a question,
what are generally the colour of crystals when crystals is the main inclusion in a VS graded diamond verses a SI graded diamond?

eg are most crystals in SI diamonds black specks ?!?

 

[strmrdr]

The most common would be other diamonds.
They can range from clear to yellow to brown.

 

[FB.]

Crystal inclusions are variable. Some are black. Some are white. Some are reflective and they can be silvery-white when reflecting light from one angle, yet black from another angle when there is no light to reflect.
Clarity grade isn't connected to the colour of the crystal inclusions, although darker and more prominent inclusions are more likely to be a lower clarity grade on acount of them being more noticeable.

I have a 1ct VS2 in front of me that has a cluster of small black crystals under the middle of the table. The stone is "eye clean", but if you know where to look, get the correct angle of viewing, get the light conditions just right and look from a distance of six inches, you can see a miniscule black speck of something.
But unless you set up the viewing conditions precisely, you can't see any hint of the inclusions. The black crystals are most easily seen with a lot of light coming into the stone to contrast the black against the white light return.
I estimate the crystals to be in an area of 0.1 x 0.2mm and they are always completely black in colour.

 

[glitterata]

My grandmother''s diamond has a reddish honey-brown comma-shaped crystal in it. But they''re more often black or clear.

 

[WinkHPD]

Those "black" inclusions are often a dark red color in transmitted light. Although often called carbon spots, the diamond itself is carbon and the inclusions that are "black" are often red garnet crystals.

Wink