Lesser-known and rare gems are not neglected, however, and he has compiled a fairly exhaustive list of gemstones, complete with color, hardness, density, refractive index, crystal system, and chemical ...

Durability is a gemstone’s ability to withstand wear, heat, and chemicals. Durability consists of three properties: hardness, toughness, and stability. Hardness means how well a gemstone resists ...

Stones are ranked according to the Mohs hardness scale, with diamonds scoring a perfect 10. (The next hardest stone, ruby, is four times less durable than diamond—but still comes in at a 9.) A stone ...

The sample was cut into a gemstone weighing 1.61 carats for further studies. Kyawthuite has an asymmetrical structure and a ...