I just noticed you are in the UK, so maybe this would be a better reference for what you have:
https://www.nobleknight.com/P/214742929 ... UK-EditionThe back of the box says "two twenty-sided dice," but presumably this means numbered 0-9 twice. The photo looks more-or-less-like your D20-percentiles (solid, not "gem"), but your green die looks lighter in color. Hard to say, as the photo might be a mock-up with different dice than what were sold.