The depth of the coloration of sapphires and other stones was believed to indicate their degree of “ripeness,” the pale stones being “unripe.” As an illustration of this, Cardano instances a sapphire he had examined, a small part of which was blue, while the rest resembled a diamond. Specimens of this kind exist in several collections.[709] The writer has seen many that are dark blue when viewed from above, and almost white when viewed through the back. The Cinghalese lapidaries had very cleverly cut a crystal that was white, with a thin coating of blue, so that the blue was at the back, fully realizing the wonderful dispersive power of the sapphire, and that it would appear dark blue if viewed from above. The value was naturally only trifling compared with that of a perfectly even-colored gem. Al-Berûnî (973–1048 A.D.) gives as the hues of the “red _yakut_” (ruby), pomegranate-colored safran (henna), purple, flesh-colored, rose-colored, and of the shade of a pomegranate blossom. Other colors of the _yakut_ (corundum crystals) were yellow (Oriental topaz), gray, green (Oriental emerald), white (white sapphire), and black. A henna-colored _yakut_, if weighing one mitqal (about 24 carats), was valued at 5000 dinars ($12,500), if its weight was half as much, or about 12 carats, it was esteemed to be worth 2000 dinars ($4500), but for one weighing as much as 2 mitqals (48 carats) no definite price could be given, probably because of its great rarity and costliness.[710] The Sanskrit name for the topaz, _pita_, signifies “the yellow stone.” This Sanskrit word is thought by many to be the original of the Hebrew _pitdah_, a stone of the high-priest’s breastplate. Another Sanskrit name is pushparaga, “flower-colored.”[711] It must be borne in mind, however, that these names refer not to our topaz but to yellow corundum, or Oriental topaz, as it has often been called. A topaz of exceptional size is that known as the “Maxwell-Stuart Topaz”[712] from the name of the owner. It was brought from Ceylon to England with a lot of inferior rubies and sapphires for use in watchmaking, and was believed to be simply a piece of quartz. So little was it appreciated that when sold at auction it only brought £3 10s. ($17.50). When on closer examination its true quality became apparent, the owner decided to have it cut in brilliant form. The operation required twenty-eight days’ consecutive work, the diamond-wheel being used, and resulted in the production of a fine cut stone of a pure white hue, weighing 368³¹⁄₃₂ carats. When the cutting was partially completed, a “feather” became apparent that would have spoiled the table, but as it was still possible to reverse the position of table and culet, this was done, and the “feather” removed. At this time, in 1879, this topaz could lay claim to being the largest cut stone in existence, although its size is considerably surpassed now by that of the largest Cullinan diamond, 516½ carats.