diamond

noun

• 1a precious stone consisting of a clear and typically colorless crystalline form of pure carbon, the hardest naturally occurring substance.
• a tool with a small diamond for cutting glass.

Diamonds occur in some igneous rock formations (kimberlite) and alluvial deposits. They are typically octahedral in shape but can be cut in many ways to enhance the internal reflection and refraction of light, producing jewels of sparkling brilliance. Diamonds are also used in cutting tools and abrasives

• 2 [often as modifier] a figure with four straight sides of equal length forming two opposite acute angles and two opposite obtuse angles; a rhombus:decorative diamond shapes
• (diamonds) one of the four suits in a conventional deck of playing cards, denoted by a red diamond.
• a playing card of the suit of diamonds:she led a losing diamond
• the area delimited by the four bases of a baseball field, forming a square shape.
• a baseball field.