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All About the Rough--Can you tell the difference?


Some of you may recall previous posts I made regarding a rock I found in Idaho…This is a follow-up for those posts:

I wanted to start this post off with a couple pictures of known rough diamonds.

The stone in the top picture above is named “Constellation”–a 813 carat diamond found in Botswana. The second is named “Lesadi La Rona”, also found in Botswana, and is the second largest gem quality diamond found weighing 1,111 carats. I find them very similar to my pieces, shown below.
Please note: All of the pieces shown below are of the same parent rock, and have been broken, tumbled, and splintered to achieve their current state. No edits or alterations have been made to any photos

The above and below photos are of the same stone but different angles. Above, the natural graining is apparent, and its crystal habit, cleavage angle, and transparency are identifiable. Below, the stone reflects the light differently, and thus, the refraction of light through the stone is altered. Note the geometric pattern the illusion illustrates.

The picture below shows the stone is indeed transparent and colorless. The octahedral faces (pyramidal-like) and distinguishable grain lines are shown here, as well. Please note the reflection at the base. This phenomenon is caused by its high refractive index. Likewise, any surface fractures or irregularities cause light to bend in such a way that results in the “cloudy” appearance seen in most pictures.

The picture below displays a greasy luster and crystal habit, among other traits.

The picture below shows it’s transparency and cubic crystal structure. “Gems with an isometric or cubic crystal system, like diamonds, have only one RI since all the axes of its cubic structure are equal in length. They aren’t doubly refractive and, thus, have no birefringence.” (IGS)

Note: “However, it has long been documented that diamonds often show weak birefringence…Dislocations, lattice parameter variations, inclusions, fractures and plastic deformation are the causes of strain-induced birefringence in diamonds.” (GIA)

The final picture is a grouping of some of the pieces broken from one large rock. I have spent almost 4 years investigating what it could be, and every characteristic, habit, or trait that identifies a diamond is apparent, in my opinion. Thanks for reading!

Please visit a few of my resources for further reading:



Here is a link to the previous posts:


I would send it to GIA for a real identification.


Here’s a good article on Identifying Diamond Rough that you might useful:

Also I have seen in a Diamond hunting documentary the use of a Diamond tester as mentioned in the article for verifying diamonds . Provided you buy good quality tester they can be pretty accurate, so worth considering.


Thank you for your feedback, vfuller. Unfortunately, the GIA labs don’t offer a test for rough stones. They do offer some tests that could possibly be used for identification, but they cost thousands of dollars. I believe the lack of response has said enough…

Joshua Williams


Hi Jason,

Thanks for your recommendation, and yes, that is a good article. I have read it and found some useful information. There isn’t a lot of literature out there regarding diamonds, so suggestions are always appreciated!

Joshua Williams



I have verified with GIA that they do in fact identify rough diamonds, the price is based on carat weight. My thought is having a 25 carat stone with hundreds of thousands of dollars and your concern is it would cost a couple of thousand dollars. It just does not make sense. Out of curiosity what county did you find this in Idaho? Was it alluvial or in kimberlite?
It would seem to me that there is an avoidance to verify the stone as diamond. I guess my other confusion is why you are posting this on here for evaluation when that is virtually impossible.
Anyhow I wish you the best.


Thank you, Mr. Fuller. I am pursuing my path elsewhere.

Joshua Williams


Not a diamond. Anyway, you were not supposed to post on here again about this stone unless you got a boni fide Lab Report on it first. That is what the Moderator told you in writing when he closed the last discussion on you. Remember?! :))))))


Why are you responding 7 months later? Still on your mind, I see…