Diamond: The Hardest Natural Material, and a Shape With Four Sides
A diamond is a precious stone made of pure carbon. It is the hardest natural substance, and the same word names a rhombus, a card suit and a baseball infield.
A diamond is crystallised carbon — the same element as graphite, arranged differently. That arrangement is everything: graphite is soft enough to write with and diamond is the hardest natural material known, and the only difference is how the atoms are bonded.
- A precious stone. *A diamond ring.*
- A rhombus shape. *A diamond pattern.*
- A suit of playing cards. *The ace of diamonds.*
- A baseball infield. *Meet at the diamond.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | diamond | A flawless diamond. |
| Adjective | diamond | A diamond necklace. |
| Compound | diamond jubilee | A diamond jubilee. |
| Compound | diamond wedding | Their diamond wedding. |
| Related | adamant | Adamant refusal. |
How it is used in a sentence
- Diamonds are graded by cut, colour, clarity and carat.The four Cs of the trade.
- A diamond in the rough.Someone with promise but no polish.
- A diamond jubilee marks sixty years.As opposed to a golden jubilee at fifty.
The four Cs
- Cut — the proportions and finish, which determine how it returns light
- Colour — graded from colourless down through faint yellow
- Clarity — the number and visibility of internal flaws
- Carat — the weight, at 0.2 grams per carat
- Cut is the only one determined entirely by human skill
From Greek *adamas*, unconquerable, through Latin and French. The same Greek word gives English adamant: someone adamant is, etymologically, as unyielding as a diamond.
Are diamonds really rare?
Less than their price suggests. Supply has been tightly controlled for much of the last century, and marketing did the rest.
Diamond or rhombus?
Rhombus is the geometric term. Diamond is the everyday word, and usually implies the shape standing on a point.