Just spotted this. Very nice, but It's a form of opal, colloquially known as "Yowah nuts" in Australia, not a seed from a tagua palm. Tagua palms also aren't indigenous to Australia.
Sorry, should have been more specific about it being an opal. I got it from a dealer who lived in Yowah. They can have some incredible patterns. He showed me pics of his mine, it started as a flat lot, and they dug a trench through it and found an opal bearing layer around 16 to 18 feet deep. Every one of the opal are unique.