Evasive “Big Ones”
The poor average yield of the peridotite matrix was not the only disappointing feature of the big Arkansas mine. In contrast with operations in South Africa and South America, no “large diamonds,” usually defined as fifteen carats or more, had turned up by 1912; and although commercial viability depended upon smaller, run-of-the-mill stones, those big ones could generate publicity and stir reconsideration among investors. Yet, the 8.1-carat gem found on the Mauney Mine in 1911 remained the record; before that it was a 6.5-carat, with a number of others only slightly smaller.
 Kunz and Washington, “Notes on the Forms of Arkansas Diamonds, American Journal of Science, 275-276, said of about 140 diamonds found to date (time of writing, Aug. 12, 1907): “The largest diamond weighs 6½ carats, and is . . . of an absolutely pure, pellucid white, free from inclusions. . . . Another stone weighs 6¼ carats, several about 5, 4, or 3, and from this they run down to 1/64 carat, the average being probably about one carat.” Fuller, “Diamond Mine in Pike County Arkansas” (January 16, 1909), 155, still reported the 6½-carat as the record find; Fuller, “The Arkansas Diamond Field [in 1911],” 6, said, “The most important event of the year was the finding of an 8ˆ-carat white stone on the Mauney tract.”