Black Sapphire

Sapphire

Sapphire is a gemstone variety of the mineral corundum, the crystalline form of aluminium oxide (α-Al2O3). Pure corundum is colorless, while trace elements in its crystal structure produce a wide range of colors. Blue is the best-known, but sapphires also occur in yellow, green, purple, pink, orange, gray, black, and colorless forms. Red gem-quality corundum is classified as ruby rather than sapphire. The boundary between ruby and pink sapphire is based on color appearance and varies among gemological and trade conventions. Sapphire has a Mohs hardness of 9, making it highly resistant to scratching and abrasion.

Black

Black is a color that results from the absence or complete absorption of visible light. It is an achromatic color, without chroma, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have often been used to describe opposites such as good and evil, the Dark Ages versus the Age of Enlightenment, and night versus day. Since the Middle Ages, black has been the symbolic color of solemnity and authority, and for this reason it is still commonly worn by judges and magistrates.

Shades of blue

Varieties of the color blue may differ in hue, chroma, or lightness, or in two or three of these qualities. Variations in value are also called tints and shades, a tint being a blue or other hue mixed with white, a shade being mixed with black. A large selection of these colors is shown below.

black

Adjective

1. Absorbing all light and reflecting none; dark and hueless.
2. Without light.

Noun

1. The colour/color perceived in the absence of light, but also when no light is reflected, but rather absorbed.
2. A black dye or pigment.

sapphire

Noun

1. A clear deep blue variety of corundum, valued as a precious stone.
2. A white, yellow, or purple variety of corundum, either clear or translucent.

Adjective

1. of a deep blue colour.
2. pertaining to a 45th year