These Mars specimens are always super popular on the page. These ones are cool because they come with more info on the back. Available for $80/box I believe these are the last of this style.

25.25 Gram Wet Ethiopian Opal with a Phantom Opal egg in the center! For some reason this piece reminds me of a clam, and the phantom is a big pearl! A cool piece for a collection. Will be shipped wet! $150. Available on @over_100_dollar_gems