INCLUSION TYPES -CAN SOMEONE PLEASE ADVISE?

[Balustroid]

This may sound silly but how many types are there? I''ve heard about Feathers (which means cracks?), Pinpoint (What''s that?!) & Cloud (Foggy?)

Which is the one to avoid? Or does it not work that way?
I''m so uneducated!

 

[dimonbob]

You don't ask for much. Here is a list:
INTERNAL (plotted in red)
Bearding
Bruise
Cavity
Chip
Cloud
Feather
Grain Center
Included Crystal
Internal Graining
Indented Natural
Knot
Laser Drill Hole
Needle
Pinpoint
Twinning Wisp
EXTERNAL (plotted in green)
Abrasions
Extra Facet
Natural
Nick
Pit
Polish Lines
Polish Marks
Rough Girdle
Scratch
Surface Graining

Which ones to stay away from is a little difficult. A feather is usually a healed fracture, not a crack, although it can be. If a feather extends across several facets, is open to the surface and it is "fracture filled" with a resin substance, I would stay away from that. If the feather is short and without color, that is a good thing. If you can see a black "carbon" spot in a diamond from three feet away, I would stay away from that. A pinpoint is a tiny speck or crystal, not visible, that is plotted by a sharp point just touching the plot paper. Some are so small that they are not plotted at all, just referred to in the comments. A cloud if visible is not exactly a good thing but many are not visible at all and are even difficult to find under 10x. You should stay away from anything that will keep nagging at you after you have purchased the diamond.

You should look at the overall clarity grade of the diamond. I VS2 and above should not have anything to concern you. An SI1 by GIA standards us "supposed" to be eye clean but that is not necessarily true.

I once did an appraisal on a 56 carat diamond that was cut like a pancake and was so full of black specks that it would have been difficult to cut a clean half carat diamond out of it. It had only two good qualities; it was a diamond and it was large.

 

[Richard Sherwood]

Excellent synopsis, Bob.

 

[pyramid]

QUOTED FROM DIMONBOB ABOVE.
If the feather is short and without color, that is a good thing.


I remember reading that if a feather had a glassy look that was a bad thing. I am assuming a glassy feather would have no coloUr to it.

I am a consumer so am wondering what dimonbob's opinion would be to this?

 

[Garry H (Cut Nut)]

There are 2 types of inclusion.....




































.










Big ones



and small ones





The way you can tell is....






Big ones are easy to see,

and
small ones are hard to see

 

[Heyjud]

Great Job Dimonbob
That's a list to amaze
Describes the way I feel some days!

Makes me want to write a great big rhyme
Using all those inclusions.....
hummmmmmm - give me some time!

 

[3hearts]

thanks for the great list dimonbob. I was considering buying an 8* SI1 that had a feather as one of the inclusions. I really wanted the stone, but the feather inclusion really bothered me...

 

[Garry H (Cut Nut)]

Some feathers are Twinning Wisp's.
Maybe that sounds better?
They look the same

 

[Balustroid]

dimonbob, I am impressed with your answer.

CutNut, your answer is quite straightforward. I'll bear it in mind!

 

[Garry H (Cut Nut)]

Did you say you will bare your behind?

Please, I am not being serious. In my own sick sort of way I find the clarity religion thing all very pedantic.
I happen to not subscribe to the idea that one type of inclusion means a diamond will be more or less durable than another.

We have had some killer debates on this topic round these parts. Lots of fear mongering, but little or no evidence ever given to show that inclusions grow etc.

I toured the biggest contract sawing factory with Paul from Antwerp and asked the head marker what happened to the stones that got

bad marks for polarisation strain. He said they treat them more carefully when sawing them. I asked how many break and he had to think hard of the last time he called a client to say your diamond died.

 

[in_need_of_help]

I am confused, is a cavity necessarily internal or can it extend to the surface?

Which is worse and why?

How much value is detracted from either scenario?

Thanks.


In_need_of_help

 

[dimonbob]

"I am confused, is a cavity necessarily internal or can it extend to the surface?"

A cavity is like a pit in the surface of the diamond extending into the diamond. It can be as small as a needlepoint in the surface or a large hole big enough for a match head. Cavities are not dangerous or necessarily bad. The problem is some of them can collect dirt and stuff and need cleaning out. Cavities are either a void that breaks the surface or a pulled crystal. They have no color.

 

[in_need_of_help]

Cavities are not dangerous or necessarily bad. The problem is some of them can collect dirt and stuff and need cleaning out. Cavities are either a void that breaks the surface or a pulled crystal. They have no color.

-----------------------------------------------------------------------------

Cavities are not dangerous or necessarily bad.
Doesn't a cavity in the surface of a solid weaken it structurally? How can this not necessarily be dangerous or bad? Can the cavity spread???

The problem is some of them can collect dirt and stuff and need cleaning out.
I am looking at a diamond with a cavity on the edge of the stone on a star facet. On the GIA cert. the cavity is pretty small. Is a cavity in this region a concern? Can it/should it be covered with a prong.

They have no color.
I imagine, when they collect dirt and stuff, its more easy to see them.


Please provide whatever feedback you can.

Thanks!

In_need_of_help

 

[dimonbob]

Q-Doesn't a cavity in the surface of a solid weaken it structurally?
A-No
Q-How can this not necessarily be dangerous or bad? Can the cavity spread?
A-No, the cavity cannot spread. If you could look inside of the cavity with enough power under a microscope, you would see that the walls are part of the cubic system and not just a hole.

I am looking at a diamond with a cavity on the edge of the stone on a star facet. On the GIA cert. the cavity is pretty small.
Q-Is a cavity in this region a concern?
A-No - What is the GIA clarity grade of the diamond??
Q-Can it/should it be covered with a prong.
A-I would not cover the cavity with a prong. If you did it would make it more difficult to keep it clean.

They have no color.
I imagine, when they collect dirt and stuff, its more easy to see them.
A-If dirt is in the cavity, yes it is more easily seen. That is why you need to keep your diamond clean.