While panning for gold in Wyoming, a few prospectors have instead found raw diamonds in their pans. Along with the United States, diamonds can be found in at least 13 countries either loose in rivers and on beaches or encased in rock or other material. Looking in the right places and knowing what to look for may yield a raw diamond.
Learn How to Identify Rough Diamonds. So do not try scratching glass with the suspected diamond. The only hardness test that will identify a diamond is scratching corundum.Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale.
Diamonds form isometric crystals, have a specific gravity of 3.1–3.5, rank 10 on the Mohs Hardness Scale, stick to a grease table, and, in some cases, fluoresce under shortwave ultraviolet light. Correctly identifying an uncut rough diamond uses a combination of these characteristics.
Scratching determines the hardness of the stone, which is a key identifying characteristic for diamonds. A raw diamond looks similar to the expertly cut stones adorning necklaces and rings. At first glance, a rough diamond resembles common quartz or calcite. Diamonds are famous for their hardness, however, and this characteristic is easy to test.
Perhaps you’ve heard or read about rough diamonds (or raw diamonds, as some people call them). If you’re wondering how these stones are different from the ones regularly sold in the jewelry store, read on. Let’s see what rough diamonds are, how you can identify them, and whether you can buy a rough diamond.
Whatever tests you choose to have performed, the best and most reliable way to tell if a diamond is real is to check the paperwork and speak to the gemologist or the appraiser. Certification and grading assures you that your stone has been "proven" real by experts.
This is probably one of the easiest, although not conclusive, ways to find out whether your diamond is real or not. For the floating test, you need a loose diamond and a glass of water. If the diamond is real, it will drop to the bottom of the glass due to the high density of the stone.
Refractive Index: For diamonds this is 2.417 to 2.419. You'll need a very flat polished face for this test and a refractometer. Since this is a rough stone you aren't likely to have a good enough face. Double Refraction test: using a polariscope you can test for single or double refraction. Diamonds are in the cubic system and singly refractive.