Rhaenyra,
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sounds like you owe me a 50 coin finder's fee. I'm just sayin'. grin

Joy42,
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They're grouped by rarity - a common group, a less common group, and an even less common group. But within those groups they don't sit in any particular order in the Museum. With the minerals, it seems that the little pedestals fill up from left to right within their groups. With bugs, that's not true, but they don't have assigned spots either. It's a mystery!