BAYLDONITE
Bright chartreuse-green masses occasionally from the copper mines near Tsumeb, S. W. Africa, in cabochon grade; rare; collectors’ gem only.
BENITOITE
Only known source of facet-grade crystals is at Dallas Gem Mine, San Benito County, California; rarely available except in small fragments seldom over 2-3 ct.; relatively soft; collectors’ item. Largest gem known 9 ct.; cut gems under i /2 ct. common; over 1 ct. rare and over 3 ct. extremely rare. Usually blue but a very few crystals have provided colorless faceted gems.
BERYL
Standard commercial gemstone; hard, durable, colorful; provides fine jew¬elry gems and small carvings. By far most expensive variety is emerald, ranking ibove diamond in large richly-colored examples; blue aquamarine highly prized but traces of green drastically reduce value (however, some rich yellow-green aquamarines are heat-treatable to fine blue); golden beryl and morganite only moderately valued, goshenite very low value. Most apricot- or peach-colored beryls, commonly called morganite, fade to pink upon exposure to strong light, the final hue depending on richness of original hue. Aquamarine sometimes contains plate-like brown inclusions capable of creating weak to moderately 5trong stars; catseyes occur in practically all varieties. Largest clean rough pro¬vided by aquamarine, sometimes in crystals of many pounds weight; also large clean crystals in golden beryl, more rarely in morganite and goshenite. Emerald crystals rarely clean when over 1/4″ diameter, but reasonably clean crystals of nearly 1″ diameter have been found.
AQUAMARINE
Supplied almost exclusively by Brazil; also from Madagascar, and sometimes from scattered  deposits  in   the  United  States  and  Australia;   occasionally  in
gem gravels of Ceylon and Burma. Finest blue grade, absolutely without trace of greenish tinge, is sometimes called “Fortaleza” after source in Brazil. Price; drop rapidly with smaller rough and as greenish tinges enter.
EMERALD
Principally from Colombia; also small crystals from Brazil, India, Rhodesia, the last of deep color and suitable for small cut gems; prices ascend steeply according to size and color, the prized color being a deep bluish-green or “Muzo” color, also deerj vellow-ereen  CSandawana. Rhodesial.
SYNTHETIC  EMERALD
Deep to medium green crystals grown by hydrothermal and flux-fusion meth¬
ods; virtually indistinguishable from natural emeralds except through careful
testing; growth methods are costly and slow, resulting in sustained high prices.
GOLDEN   BERYL   (HELIODOR)
Ranks low commercially because the color is not greatly favored for jewelry and resembles that of citrine; large color variations from greenish-yellow to golden yellow to pale yellow; a yellow with a reddish cast is more highly prized. A deep yellow kind has been called heliodor. Principally from Brazil;
GOSHENITE
This colorless variety is cut mainly for collectors;    it is not used commercially.

GREEN   BERYLS
This varietal name embraces deeper-hued green    beryls, ranging from char¬
treuse to somewhat brownish-green types, some of    which are capable of heat
treatment to blue. Paler kinds are generally classed under aquamarine.
MORGANITE
Includes true pink, also peach, apricot, and other orange tints which fade to pink or can be heat-treated to pink; occasionally available in flawless rough large enough to cut gems over 100 ct.; veil-type inclusions common. Ranks low commercially because most cut gems are too pale; the finest pinks occur in Madagascar.
STAR  BERYL
Aquamarine containing numerous very small plate-like crystals of brown hematite parallel to the basal plane and furnishing weak to good stars when properly cut; not all specimens produce stars; rare.

BERYLLONITE
An excessively rare phosphate mineral obtained only from one deposit in Maine as cleavable colorless crystals and fragments up to 2″ diameter; soft, brittle; suitable only for collectors’ gems. Cut gems over 5 ct. very rare.

BINGHAMITE, See QUARTZ BLOODSTONE, See QUARTZ BORACITE
Only from saline deposits of Germany as very pale bluish-green  corroded
crystals not over 3/8″ diameter which provide attractive facet gems;  very rare; collectors’ gem only.

BORNITE
Known as “peacock ore” because of iridescent tarnish film which quickly de¬
velops on fracture and cabochon surfaces; soft, brittle; collectors’ item only.

BOWENITE, See SERPENTINE BRAZILIANITE
Soft, cleavable phosphate mineral in greenish or pale yellow to rich yellow crystals; only from Brazil in cuttable specimens; collectors’ item; largest gems 20-30 ct.
BREITHAUPTITE
A sulfide mineral furnishing brilliant metallic luster cabochons, soft;  COIICM tors’ gem only.

BRONZITE, See HYPERSTHENE BROOKITE
Very small crystals very rarely clean enough to facet; not commercially avail¬able.
BYTOWNITE, see FELDSPAR CACOXENITE, See QUARTZ CALCITE
Clean crystals provide faceted gems of interest only to the collector; some purplish-pink massive material of considerable translucency has also been faceted; much massive, banded calcite is employed in ornaments ranging from wall panelling, counter tops, and pedestals, to book ends, desk stands, and spheres; such material is commonly called calcite onyx; brownish types, usually obtained from cave deposits, are called cave onyx; some onyxes are available in blocks of several tons weight; chatoyant material is called satin spar.