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Baddeleyite: ZrO2Baddeleyite ©gemfrance.com
Etymology : from Joseph BADDELEY’s name who brought the first samples from Sri Lanka.
Discovery in 1892 from Fletcher in Kommonnangam, Rakwana, Sri Lanka.
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Bahianite: Al5Sb3+5O14(OH)2
Authors : Moore and Iraki in 1978.
Etymology : the name comes from the standard locality, Bahia in Brazil.
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Bastnaésite: バストネサイト (Ce,La)(CO3)FBastnaesite ©gemfrance.com
Etymology : this name is coming from the localty of discoveryprovenant : Bastnas, Riddarhyttan, Vastmanland, Sueden.
Discovery by Huot in 1841.
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Baryte: 重晶石 Ba SO4 Baryte ©gemfrance.com
Baryte is the most common barium mineral, discovered in hydrothermal, sedimentary and secondary veins.
As the name derives from greek "barys : heavy", baryte is a well heavy mineral. Over 80% of bayte is used as a drilling mud for oil and gas wells. And used in the manufacture of paints, some floor coverings and textiles, and as a filler for paper. As "barium meal" in medical X-ray photography.
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Benitoite: ベニト石 Ba Ti (Si3 O9).Benitoite  ©gemfrance.com
Etymology : locality where it was discovered in 1907 : San Benito County, California, USA.

Beryl グリ Be3Al2Si6O18.
Beryl is a mineral composed of beryllium silicate and aluminium. Its name comes from the Sanskrit "bêrullos". This name comes from the city of Vellore, situated 100 km to the west of Madras, India.

Green beryl is named Emerald, blue beryl Aquamarine, pink beryl Morganite, white beryl Goshenite, red beryl Bixbiite, and yellow beryl Heliodore.

_A green beryl that doesn’t contain either chromium or vanadium can not be named an Emerald and must always be called « Green beryl ». _There exists a photosensitive blue beryl called « Maxixe beryl », discovered in 1917 in the Maxixe mine, Minas Gerais state, Brazil. This dark blue beryl loses its color and fades to a light yellow when exposed to sunlight. The color can be temporarily restored by the irradiation of the stones, although exposure to sunlight will once again fade them to yellow. _In 2003, the discovery of a dark blue beryl in the Yukon, Canada was made. This beryl has been named « True Blue » and apparently owes its color to an unusually high concentration of iron in the stone. _Another unusual beryl is « Riesling beryl », discovered in Germany in the 1840’s. This beryl is a pale green color with a golden yellow flash. Other pockets of similar colored beryl were discovered in Brazil in 2002 and 2004, although some collectors don’t consider it true Riesling beryl, and the price of the Brazilian material is nowhere near that of the German material.

Beryllonnite: ベリロナイト Na Be PO4Beryllonite ©gemfrance.com
Etymology : because beryllium is part of its chemical composition.
Discovered by Dana in 1888. The standard locality is Mt. Mckean, Stoneham, Oxford co., Maine, USA.
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Bilanga:
Locality giving it’s name to a meteorite.Bilanga ©gemfrance.com
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Birthstone
For each birth month, there is associated a birhstone :

-  January: Garnet;
-  February: Amethyst;
-  March: Aquamarine;
-  April: Diamond;
-  May: Emerald;
-  June: Pearl;
-  July: Ruby;
-  August: Peridot;
-  September: Sapphire;
-  October: Opal;
-  Novemebr: Topaz;
-  December: Turqoise.

Bixbite:Bixbite - Red beryl  ©gemfrance.com
Etymology : was discovered in 1897 by Maynard Bixby.
The red variety of the beryl group. Some people improperly call it « red emerald ». This commercial name is forbidden, the name of « emerald » being strictly reserved for beryl containing chromium or vanadium.
Red beryl was discovered in the topaz deposits of Utah. It is the only mine where gem quality crystals are found.
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Bolivianite:
Commercial name for the Ametrine.

Brillant diamond cut:brillant diamond cut
The round brillant cut is used for diamonds or stones cute like round diamonds.
You may have heard of a term called "Ideal Cut". This term refers to the attempt to cut a diamond into the best proportions to achieve maximum brilliance. The following is a breakdown of what is considered "Ideal Cut" in round brilliants according to "American Ideal / Tolkowsky" and the "European Ideal Cut" (Proportions are given relative to the girdle diameter)

American ideal - Tolkowsky European ideal
Total depth58.7 to 62.3%60.0 to 61.1%
Table diameter53.0% to 58.0%57.5%
Girdle thicknessMedium to slightly thickVery thin to medium
Culet sizeNone to mediumNone to medium
Crown angles34.3° to 34.7°34.5°
Pabillon depth43.1%43.1%
FinishVery good to excellentGood to excellent
Crown height16.2%16.2%

There are 58 facets in a Round Brilliant Cut including the culet. On the Crown or upper part of the Diamond, these consist of 1 table facet, 8 bezel facets, 8 star facets, and 16 upper girdle facets for a total of 33. On the pavilion, or bottom part of the diamond, there are 16 lower girdle facets, 8 pavilion main facets and 1 culet.

Bustamite: バスタマイト (Mn+2,Ca)3 Si3 O9Bustamite ©gemfrance.com
Dedicated to A. BUSTAMENTE, the Mexican who sent the species to the National Museum National of Natural History in Paris. Species discovered in 1822.
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Bytownite: (Ca,Na)(Si,Al)4O8Bytownite ©gemfrance.com
Etymology : from Bytown, the former name of Ottawa - Ontario - Canada. Discovered in 1831 by Thomson.
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