An opal cabochon is a type of opal gemstone that's been cut and polished into a smooth, rounded shape, typically without facets. Here's a brief overview:

Key Characteristics:

1. Appearance: Opal cabochons often display a mesmerizing play of colors, known as opalescence, which can appear to shift and move as the stone is turned.

2. Cut: Cabochon cuts emphasize the opal's color play and patterns, rather than brilliance or fire.

3. Polish: A high polish enhances the opal's appearance and showcases its unique color patterns.

Types of Opals:

1. White Opal: Displays a white or light body tone with vibrant color play.

2. Black Opal: Has a dark body tone, making color play more dramatic.

3. Fire Opal: Displays vibrant red, orange, or yellow colors.

Care and Maintenance:

1. Handle with care: Opals are relatively soft (5.5-6.5 Mohs hardness) and require gentle handling.

2. Avoid harsh chemicals: Clean opals with mild soap and water.