When valuing an opal, whether it’s a black opal, white opal, crystal opal etc, brightness is one of the most important factors. Opal brightness is graded on a scale from B1 to B5, and it plays a major role in determining the gem’s price.
🤔 Understanding the Brightness Scale (B1 -> B5)
- B1 - Subdued: Very dim colour. You’ll need strong lighting or direct sunlight to see the play‑of‑colour clearly.
- B2 - Moderate Bright: Colour is visible but still quite soft. You can see the play‑of‑colour in decent lighting, but it won’t stand out strongly.
- B3 - Bright: A balanced, noticeable brightness. The colour shows well in normal indoor lighting and becomes more vibrant in natural light.
- B4 - Very Bright: Strong, lively colour that stands out clearly in most lighting conditions. A high‑quality brightness level often seen in better black opals, crystal opals and boulder opals.
- B5 - Vivid: Extremely vivid colour that stands out even in low light. High‑brightness opals often look incredible in the shade and are the most valuable.
To see more on colour grading check out the video below where I cut a rough opal (from Lightning Ridge, Australia) into a finished stone (with a Brightness of 3) 👇
🔍 What to Look for When Buying an Opal
Whether you're shopping for opals, always check the brightness rating. Strong LED lights can make an opal appear brighter than it really is, so reputable sellers should clearly list the true brightness level.
In general, the brighter the opal, the higher the value - especially for premium stones like Lightning Ridge black opals, crystal opals, and boulder opals.
If you're buying online, look for sellers who specialise in Australian opals, provide accurate grading, and show the stone in natural lighting.