What is the transparency level of gray-base black opal?

The transparency level of gray-base black opal is accurately described as translucent to opaque. This means that while the stone may allow some light to pass through, it does not permit clear visibility of objects through it, typical of fully transparent stones.

Gray-base black opals often possess a dark body tone that lends itself to an opaque appearance, which enhances their vibrant play-of-color. The combination of translucency and opacity allows these opals to display their unique internal structure and colors effectively, but they do not reach the level of clarity found in transparent gemstones. This characteristic makes them distinct within the broader category of opals, defined by their darker body colors that can affect light interaction.