The finest Persian cylinder, the oldest known form of seal, known was made out of this stone. In these antique works, the sapphirine or blue chalcedony was preferred to other varieties. Consequently, antique chalcedony is often found bearing the most elaborate engraving. Its combined hardness and toughness lent the stone to engraving, making it the perfect stone for seals. Leonardus in the 1500s says that the blue gem “delights the eyes with its agreeable embellishments.”Ĭhalcedony was of wide use and high value in antiquity. King says that the sapphirine is “an extremely pretty stone, often approximating to a pale sapphire in color.” Another blue gemstone called praconissus must have been the banded blue chalcedony. In his commendation of the blue stone, C. On account of its color, blue chalcedony was called sapphirine. Blue chalcedony, the most popular of blue gemstones for seals Between these two, it was the pale blue gem that was esteemed the most. Chalcedony in reality occurs in many colors, but the name is reserved for the white or pale blue stones. Translucent in clarity, the blue gemstone is waxy in luster, hard and tough. Chalcedony is the name for the cryptocrystalline or obscurely crystalline quartz. Of the varieties of a stone called chalcedony, the blue stone was deemed the best. THE BLUE DIAMOND : From Misfortune to Eternal Love.Indeed, a decidedly blue color enormously augments the value of a diamond. If the diamond is not only slightly tinged but of pronounced color, this blue stone is among the most valuable of gems. As a norm observed to this day, a bluish tinge affords the diamond higher value than a yellowish impurity would. Still, on account of the same rarity, later centuries saw the rise in value of the blue diamond. The blue gem was the least valuable of all. Even when Europe and Asia had known blue diamond, they did not appreciate the blue crystal as much as they did the rest of its kind. The first known, as well as the most famous blue diamond, is the Hope Blue, which Tavernier brought out of India in 1642. The reason why blue diamond places low on our list is the fact that the blue stone was unknown and thus not appreciated by the ancients. Blue diamond, the hardest of these beautiful blue gemstones From Hadysemaan, CC BY-SA 4.0 King thus finds the blue diamond much superior in beauty. Indeed, this variety of diamond boosts of a color that emulates that of sapphire, and goes on to surpass the latter with its unrivaled hardness and adamantine luster. The blue stone shares the extreme hardness and refractive index of the pure white, but has its cool blue color to set it apart. Next to the red variety, blue is the rarest color of diamonds. One indeed needs to watch out for these enhanced blue stones sold in the market as December’s birthstone. Most of the blue gems in the market were in fact colorless, gray or brownish topaz that went through heat treatment. However, topaz can be treated to produce a strong blue shade. Blue topaz, one of the rarest of blue gemstones From Gemsphoto, CC BY-SA 4.0īlue topaz is a gem pleasing to the eye and extremely rare. The blue stone thus follows yellow topaz in the calendar of birthstones, where the former sits as December’s gem next to its yellow cousin, the birthstone of November. Although not in an official pronouncement, Americans popularly consider blue topaz as one of December’s birthstones. While the color typically associated with topaz is yellow, topaz also occurs in blue crystals. Topaz is a transparent blue gem of a vitreous or glassy luster. In 2002, just over 34 years after its discovery, America added tanzanite as alternate birthstone for December. Though discovered not so long ago, tanzanite was catapulted to prominence after the blue stone was inserted into the list of month stones, whose origins in fact go back to time immemorial. Tanzanite, the newest of these beautiful blue gemstones From Wiener Edelstein Zentrum, CC BY-SA 3.0 This blue crystal from Africa is noted for its optical quality called pleochroism, in which a single tanzanite changes from blue to violet, and even burgundy, depending on the crystal’s orientation. Named after Tanzania, where the glassy gemstone was first unearthed, tanzanite ranges in shade from blue to violet. Tanzanite is a popular blue gem discovered only in 1967. With azurite achieving a hardness of only 3.5 to 4 in the Mohs scale, there is little wonder how the lapis Armenus was “easily broken.” With a specific gravity of 3.7 to 3.9, the lapis Armenus is indeed also “light in the handling.” It is these inferior hardness and toughness that render the blue semi-precious stone less suitable for jewelry. As Leornadus states in the 1500s, lapis Armenus is light in the handling and easily breaks. The weakness of this strikingly blue gemstone lies in its hardness.
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