Hobbies And Interests
Hardness
The Mohs hardness scale defines the hardness of a mineral and has been used since 1822. The scale ranks from 1 to 10, with higher numbers indicating a higher hardness. The hardest mineral, with a hardness of 10, is the diamond. Rubies, which are a type of corundum mineral, have a hardness of 9. This means that the only mineral that can scratch a ruby is a diamond. All other minerals with lower hardness scores are too soft to do so.
Luster
Luster is the characteristic used to describe the surface of a mineral in regard to its reflective properties. Rubies can exhibit a range of luster. All rubies reflect light well and are shiny as a result. Some are adamantine, meaning they are translucent. Others are vitreous, or glassy. Still others can fall somewhere between the two.
Composition
There are numerous types of corundum minerals, including rubies and sapphires. What makes a ruby unique is that it is composed of chrome, a rare mineral that gives the ruby its red color. Chrome also makes rubies more brittle, which causes many to break up before they can fully form. This is why large rubies are so rare and therefore are expensive.
Rubies are also composed of aluminum oxide and trace elements that depend on where they are formed. Some rubies contain rutile, which gives a silky shine and can create the effect of a six-pointed star within the ruby.
Specific Gravity
A substances-specific gravity is the ratio of the density of that substance to the density of fresh water. An object with a specific gravity of less than 1.0 will float, while an object with a specific gravity of greater than 1.0 will sink. The greater the specific gravity, the faster it will sink and the more it will weigh. Rubies, depending on their composition, have a specific gravity of between 3.9 and 4.1.