Hallmark (noun)

1. A feature or characteristic that is a typical indicator of a particular type of thing or person.
2. A stamp or inscription on gold or silver articles certifying their standard of purity.

Origin:

Late 19th century: from the name of the hall brothers, who ran a gold-smiths' business in london and became known for marking their gold and silver with a distinctive mark.

Examples:

1. A hallmark of a good leader is their ability to make decisions in a timely and effective manner.
2. The hallmark of her cooking is the use of fresh ingredients and bold spices.
3. The hallmark of this brand of chocolate is its smooth and creamy texture.
4. The hallmark on this piece of jewelry indicates that it is made of 14 karat gold.
5. The hallmark of his success is his relentless work ethic and his unwavering commitment to excellence.