agate, in a crown or bezel setting.

Agate is a natural gemstone that is commonly found in the form of a cabochon, which is a smooth and rounded shape. In a crown or bezel setting, this gemstone can be used to create beautiful and unique jewelry pieces. The iridescent and colorful bands of agate make it a popular and eye-catching choice for jewelry designers looking to add a touch of elegance to their creations.