diamond

A glimmering glass-like mineral that is an allotrope of carbon in which each atom is surrounded by four others in the form of a tetrahedron.

The saw is coated with diamond.

synthetic diamond

A gemstone made from this mineral.

The dozen loose diamonds sparkled in the light.

Although there are dozens of different types of gems, among the best known and most important are diamond, ruby and sapphire, emerald and other gem forms of the mineral beryl, chrysoberyl, tanzanite, tsavorite, topaz and jade.

A diamond ring.

What a beautiful engagement diamond.

A very pale blue color.

Sable, when blazoning by precious stones.

Elphingston. Pearl a Chevron Diamond between three Boars Heads Eraz'd Ruby, arm'd of the first. / Eymouth. Diamond a Lyon Rampant Pearl, on a Canton of the 2d, a Cross Ruby.

The Field is Ruby, on a Bend Topaz, three Martlets Diamond. The Armes of the most Noble and Puissant Lord, Edward Brabazon, Earl of Meath, and Baron of Atherdee in the Kingdom of Ireland. His Lordship's Atchievements are Quarterly of sixteen Coats. 1. Brabazon, as above. 2. Diamond, on a Chevron between three Pickaxes Pearl, as many Mullets Ruby, by the Name of Mosley. 3. Saphire, ten Bezants, 4, 3, 2, 1, by the Bisset.

Made of, or containing diamond, a diamond or diamonds.

He gave her diamond earrings.

Of, relating to, or being a sixtieth anniversary.

Today is their diamond wedding anniversary.

Of, relating to, or being a seventy-fifth anniversary.

Today is their diamond wedding anniversary.

First-rate; excellent.

He's a diamond geezer.

To adorn with or as if with diamonds.