http://www.3reef.com/forums/attachm...ck-maxima-clam-riptides-reef-orablackclam.jpg
ORA black "zebra" maxima clams are rarer than your blue squammies and such. As soon as you say rare, people have pictures of teardrop maximas and all the rest, but you never see many pics of these; think about it. According to ORA, they sell all their black's (and theirs are so-so... its hit and miss as to what you end up with really) to the EU because there are more there who are willing to pay top dollar for clams unlike here where the supply of all the other clams would make paying $800 or more for a black clam seem crazy.
This is what a good zebra black maxima should look like:
http://wtfragit.com/images/37.jpg
http://www.wetwebmedia.com/ca/volume_6/volume_6_4/images/clams/MaximaBlack.jpg
http://www.orafarm.com/images/maxima_zebra.jpg
Even rarer than that, and the most rare and beautiful I would have to say, is the black galaxy maxima. Its black with little speck size spots of that glowing white/blue that makes it look like the sky at night. Ive only seen a couple ever. This one is close, but imagine all the spots as only round dots, not oblong or striped:
https://www.reef2reef.com/forums/unique-corals/47063-black-white-maxima-clam-ultra-maxima.html