Morganite
From Wikipedia, the free encyclopedia
Morganite, also known as "Pink Beryl," "Rose Beryl," "Pink Emerald," and "Cesian Beryl," is a rare light pink to rose-colored gem-quality variety of the mineral beryl (Be3Al2(SiO3)6), which is better known for its green variety (emerald) and its blue variety (aquamarine). Morganite was named for financier (and gem and mineral collector) J. P. Morgan. Orange/yellow varieties of morganite can also be found, and color banding is common. The mineral turns pinker upon high-temperature treatment.
Contents |
[edit] Discovery and naming
Morganite was first discovered together with other gemstone minerals, such as tourmaline and kunzite, at Pala, California, early in the twentieth century. This started a bonanza for these quite popular gemstones which drew the attention of gemologist George Frederick Kunz, who knew that pink beryl was quite a rarity. [1]
In 1911, Kunz suggested naming the pink variety of beryl "morganite" after J.P. Morgan (the famous financier), his biggest customer at the New York jeweler Tiffany's. [2]. Ever since, the stone has held a certain popularity with Tiffany's, though it still remains a relatively scarce gem.
By the turn of the century, Morgan had become one of the most notable collectors of gems and minerals, and had assembled the most important gem collection in the United States, with over 1000 examples of American gemstones. Morgan's collection was exhibited at the World's Fair in Paris in 1889, The exhibit won two golden awards and drew the attention of important scholars, lapidaries, and the general public. [3] Tiffany's, with Kunz as their "chief gemologist," had actually assembled Morgan's first collection. Kunz then continued to build a second, even finer, collection for Morgan, exhibited in Paris in 1900. These collections were donated to the American Museum of Natural History in New York, where they were known as the Morgan-Tiffany and the Morgan-Bement collections. [4]
Morganite is also be known as "pink beryl," or in the jewelry]] trade as "pink emerald." Attempts to change the names of beryl gem varieties were a matter of some contention in the gem trade, but this ended for morganite when National Jeweler Magazine declared in a cover story (Vol. 36, No. 12; June 16, 1994), "Morganite: It's Pink Emerald Now." In July, 2005, the auction house Sotheby International sold a 947-carat morganite Islamic prayer bead in an Islamic art auction in London, calling the gem "Pink Emerald." This was the first major auction house to use the jewelry trade term pink emerald instead of the mineral name morganite.
[edit] The Rose of Maine
On October 7, 1989, one of the largest gem morganite specimens ever uncovered, eventually called "The Rose of Maine," was found at the Bennett Quarry in Buckfield, Maine[5]. The crystal, originally somewhat orange in hue, was 23 cm long and about 30 cm across, and weighed in (along with its matrix) at just over 50 lbs[6].
This ill-fated stone was later shattered by the brothers leasing the quarry at the time of the discovery, in spite of the fact that the Smithsonian had offered a very large sum for the stone 'as is.' The remains of the stone would be cut into smaller gemstones that, all together, did not come close in value to the original offer.
[edit] Chemical and physical properties
The chemical formula of morganite is: Be3Al2(SiO3)6 beryllium-aluminium silicate.
The chemical composition of beryl is beryllium (14%) aluminium (19%) silicate (67%), usually containing alkali ions, other minerals, water, and gases. It crystallizes in hexagonal shapes, known as habit, and is in the dihexagonal-dipyramidal class of the Hexagonal crystal system. Beryls sometimes crystalize in well formed hexagonal prisms with pedion (flat) terminations. It has refractive index values of 1.57 to 1.58 with weak dichroism. Cleavage is absent to poor in one direction. The hardness is 7.5-8 on the Mohs hardness scale, and the specific gravity ranges from 2.66-2.83.[7]
Many sources attribute morganite's color to the element manganese in interstitial sites in the beryl's ring structure[8]. Other references attribute the color to the element caesium[9]
[edit] Value as a gemstone
Morganite is much rarer than other common beryls, such as aquamarine and heliodor. Its value is influenced by demand, and is generally less well known than aquamarine. Red beryl ()bixbite), also known as "red emerald," is also very rare and is primarily found in the Wah-Wah Mountains of Utah.
Morganite can be routinely heat treated to remove patches of yellow and is occasionally treated by irradiation to improve its color.
[edit] See also
[edit] References
- ^ Morganite discovery in Pala, CA, AGTA website, accessed online February 20, 2007
- ^ Morganite, International Colored Gemstone Association, accessed online January 22, 2007
- ^ Morgan and his gem collection, In George Frederick Kunz: Gems and Precious Stones of North America, New York, 1890, accessed online February 20, 2007
- ^ Morgan and his gem collections, donation to AMNH, In George Frederick Kunz: History of Gems Found in North Carolina, Raleigh, 1907, accessed online February 20, 2007
- ^ Mineralogy of the Bennett pegmatite, Oxford County, Maine, article, Citation of discovered and destruction of the Rose of Maine (see bottom paragraph of first page)
- ^ The Rose of Maine, image, The Rose of Maine at the site of its discovery
- ^ Weinstein, Michael, 1958, The World of Jewel Stones, p. 104 - 107, Sheridan House, New York
- ^ [1], article, New Mexico Facetor's Guild, accessed online March 19, 2007
- ^ Hurlbut, Cornelius S. Jr, & Kammerling, Robert C., 1991, Gemology, p. 203, John Wiley & Sons, New York
