The visual identification of rough diamonds

The visual identification of rough diamonds Manpower from the following aspects:

(1) Observe the gloss

Because diamonds have a special diamond luster, the refractive index of diamonds is as high as 2.417. There are few natural gemstones with a refractive index as high as mineral oil. The rough diamonds can see strong luster even on the rough surface, so the luster is the difference Important characteristics of other colorless and transparent minerals (or materials). The discoveries of many famous diamonds in the world are unique because of their “shiny crystal” appearance. When observing the gloss of diamonds, you should also pay attention to the fact that some rough diamonds have very developed crystal surface patterns that affect the observation of gloss. Try to observe the gloss from the smooth crystal surface to avoid illusion.

26 carat rough DE VS
The 26-carat rough DE VS, the rough diamond has a strong diamond luster, which is very bright even under ordinary light sources. The picture is provided by a friend who works in Africa.

(2) Observe the appearance and surface characteristics of the diamond

In rough diamonds, well-developed crystals occupies a considerable number. Observing the morphology of the crystals can also help us identify diamonds. The most common crystal forms of diamonds are octahedron, rhombohedral dodecahedron and the combination of the two. There are few minerals with these crystal forms in colorless and transparent minerals. Even if they have similar shapes, such as colorless spinel, garnet, etc., they can be distinguished from each other because of their other properties. In addition to observing the crystal morphology of the rough, another feature is the crystal face pattern of diamonds. Different crystal faces of diamond often have characteristic growth patterns (crystal face patterns), such as triangular growth patterns on octahedral crystal faces (see Figure b), triangles The cusp points to the octahedral crystal ridge; the cubic crystal plane often has square or rectangular growth lines, which form an angle of 45° with the cube plane; the rhombic dodecahedron crystal plane usually has grooves parallel to the long diagonal direction, etc. These can be used as identifying characteristics of diamonds.

The crystal face pattern and corrosion pits on the original crystal shape of the diamond
Figure b, the crystal surface pattern and corrosion pits on the original crystal shape of the diamond

The rough diamond
The rough diamond rough, the dissolution pit of the inverted triangle dent on the octahedral crystal surface, and the identification feature of the rough diamond.

The rough diamond
The triangular growth step of the octahedral crystal face of the rough diamond is also a characteristic identification feature

Rough rough crystal
All kinds of rough diamond rough crystals, pictures provided by African workers.

The identification of rough diamonds is mainly based on the above two basic points, understanding the basic growth principles and physical characteristics of diamonds, combined with specific suitability, the identification of rough diamonds by naked eyes is still very easy to confirm. Finally, thank you for knowing that this platform has indeed made many peers. Friends, in fact, I am still very interested in rough diamonds, and I have a feeling of returning to learning, which is very appropriate. Let me share another standard octahedral crystal of rough diamonds sent to me by an African worker. It is very large and the color is very white. It is probably FG color by visual inspection.

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