Dark 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.

Darkness

Darkness is the condition resulting from a lack of illumination, or an absence of visible light.

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.

dark

Adjective

1. Having an absolute or (more often) relative lack of light.
2. Extinguished.

Noun

1. A complete or (more often) partial absence of light.
2. Ignorance.

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