rocktumbler.com Rank 1M. Estimated value 2,220$digitalatlasofancientlife.org Rank 2.4M. Estimated value 912$whoi.edu Rank 197.8K. Estimated value 11,028$irocks.com Rank 104.5K. Estimated value 20,976$earthdoc.org Rank 442.3K. Estimated value 4,896$egpet.net Rank 576.5K. Estimated value 3,744$iris.edu Rank 94K. Estimated value 23,316$webmineral.com Rank 481.8K. Estimated value 4,488$rocasyminerales.net Rank 1.3M. Estimated value 1,704$spatialreference.org Rank 349.9K. Estimated value 6,204$