Babingtonite is a not a common mineral, and is usually associated with zeolite s. It ... More
Babingtonite is a not a common mineral, and is usually associated with zeolites. It is found as small, dark, lustrous crystals on light-colored zeolites, creating specimens of strong contrast. Such specimens are much sought after by collectors. Recent findings in China have produced some very large crystals unlike any others previously known. Babingtonite sometimes pseudomorphs into other minerals, especially amphiboles as witnessed by the abundance of altered Babingtonite at Paterson and Prospect Park, New Jersey. Hide
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Barite is well known for its great range of colors and varied crystal habits. It is e... More
Barite is well-known for its great range of colors and varied crystal habits. It is easily identifiable by its heavy weight, since most similar minerals are much lighter.
Controversy exists regarding the spelling of Barite. This mineral has always been spelled "Barite" in the United States. In the United Kingdom, the spelling has traditionally been "Baryte." The IMA originally referenced this mineral as "Barite," but then changed its spelling to "Baryte" many years later. This has been a very controversial move, with many questioning the IMA's logic behind this change. Most American mineral collectors and mineralogists still prefer the spelling Barite, and we reflect that spelling here in this guide as well. Barite specimens from certain locations are brown from sand inclusions, and may occur in beautiful rosette aggregates that strikingly resemble a flower.
These are known as Barite "Desert Roses." The mineral Gypsum also contains similar Desert Roses, but Gypsum roses are much light in weight, and are more brittle and thin.
Barite often replaces other minerals, and may even replace organic materials such as wood, shells, and fossils. It sometimes forms tufacious mounds from deposition of hot, barium-rich springs. It is isomorphous and very similar in form with the mineral Celestine, and may partially replace it.
The name Barite is derived from the Greek word barys, which means heavy, alluding to the heft of this mineral. Hide
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Bauxite is not a mineral, but rather a group of aluminum oxide s. The term is general... More
Bauxite is not a mineral, but rather a group of aluminum oxides. The term is generally used to describe the economically important mixture of these minerals, which form a mass of the individually classified members of Gibbsite, Boehmite, and Diaspore. Bauxite does not make aesthetic or interesting specimens as far as collectors are concerned, but it holds importance as being the primary ore of the metal aluminum. Bauxite is named after the French village of Les Baux, where it was first recognized as an aluminum ore. Hide
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Benitoite was first discovered in 1907, and upon its initial discovery was thought to... More
Benitoite was first discovered in 1907, and upon its initial discovery was thought to be Sapphire. The crystal structure of Benitoite is unique, and is the only significant mineral in its crystal class. It crystallizes in a rare hexagonal sub-class called ditrigonal-dipyramidal. Most Benitoite crystals were originally deeply embedded in thick Natrolite; specimens are prepared for
collectors by dissolving the surrounding Natrolite in acid to expose
the Benitoite crystals. The blue Benitoite on a white Natrolite matrix and usual association with black Neptunite makes a very aesthetic mineral
specimen. Benitoite is named after its locality in San Benito Co. in California, where this mineral was first found in a remote area far from civilization. This region is the only source of Benitoite, aside from some very sporadic and extremely limited occurrences worldwide. For additional information, see the gemstone section on Benitoite. Hide
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The images below represent all forms and varieties of Beryl except for the Emerald and Aquamarine varieties. These varieties have their own dedicated page with more photos.
Beryl is a most alluring and popular mineral. It occurs in a diversity of colors, and... More
Beryl is a most alluring and popular mineral. It occurs in a diversity of colors, and has several important gemstone varieties. The green variety, Emerald, is one of the most precious gems. Only green Beryl with a deep green color is called Emerald; light green Beryl is simply " Green Beryl" (or Heliodor if it has a yellowish color.) Aquamarine, another important gemstone, is the greenish-blue to blue variety of Beryl. Green Beryl from certain localities can be heat treated to produce sky-blue Aquamarine.
Other popular gem varieties of Beryl are the pink Morganite, and the yellow Heliodor and Golden Beryl. A deep red variety of Beryl, known as Red Beryl (or Bixbite) is extremely rare, and only comes from two localities in Utah. When in good specimens, Red Beryl commands an outstanding premium and is very difficult to obtain.
Pure Beryl is colorless. However, a wide range of impurities cause
the diverse amount of colors and many varieties. The green color in Emerald is usually caused by traces
of the element chromium, and the blue color of Aquamarine usually by iron. Beryl is naturally transparent, however inclusions and impurities may make it opaque. All gemmy transparent varieties are highly valued, but the other forms of Beryl in opaque crystals are much more common. Some of the largest natural crystals known are of Beryl, with enormous crystals having been found in several pegmatite occurrences. Hide
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Biotite is a very common form of mica . It is named in honor Jean Baptiste Biot 1774 ... More
Biotite is a very common form of mica. It is named in honor Jean Baptiste Biot (1774 - 1862), a French physicist, mathematician, and astronomer who researched the mica minerals for their optical properties. Because of Biotite's
abundance, its presence is usually lacking in collections except for it
being an accessory mineral to other minerals. Biotite can come in
enormous crystal sheets that can weigh several hundred pounds. Thin
sheets can be peeled off as layers, and the thinner a layer is peeled
the greater its transparency becomes. In 1998, the IMA removed the status of Biotite as an individual mineral species, and instead declared it as a group name for the following individual members: Phlogopite, Annite, Siderophyllite, and Eastonite. However, mineral collectors still refer to Biotite by its traditional name and rarely make a distinction among its members except for Phlogopite. Biotite is very hard to clean because if washed
it will absorb water internally and start to break apart. The best way
to wash Biotite and other Micas is with a dry electric toothbrush. Hide
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Bismuth is an uncommon mineral composed of the element of the same name. Its rarity i... More
Bismuth is an uncommon mineral composed of the element of the same name. Its rarity is about the same as Silver. It usually forms in ugly masses, though occasionally does form in aesthetic lustrous crystals. Bismuth has a metallic-white color with a slight reddish or pinkish hue. This pure color will only be present on an un tarnished (i.e. freshly broken) surface, since Bismuth tarnishes yellow to dark-gray. Most marketed Bismuth specimens are laboratory grown, and exhibit a very interesting shape. They have hopper-like growths in pseudocubic crystals, and are usually coated with chemicals to prevent tarnish, thus maintaining the silver-white color. Sometimes the coating gives a colorful effect on the bismuth. These artificial crystals are widely available to collectors, and are sometimes not labelled as being lab grown. It is safe to assume that any hopper-shaped crystal with a fine luster and no tarnish is laboratory-grown. Hide
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div Bismuthinite is an uncommon bismuth mineral that forms in interesting crystal hab... More
Bismuthinite is an uncommon bismuth mineral that forms in interesting crystal habits. It generally forms in bismuth deposits, and may even form in together with Native Bismuth. Bismuthinite is structurally similar to Stibnite, with a similar appearance, but they occur in different environments, and Stibnite can form in much larger and robust crystals. Bismutite, a bismuth carbonate mineral, sometimes forms as an alteration of Bismuthinite. Bismuthinite is named for its bismuth content.
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div Bixbyite is an uncommon mineral, distinguished by its dark, lustrous crystals tha... More
Bixbyite is an uncommon mineral, distinguished by its dark, lustrous crystals that are often exceptionally formed. The sharply formed crystals, combined with a frequently contrasting light rhyolite matrix, make this mineral very appealing to the collector.
Bixbyite is named in honor of Maynard Bixby (1853 – 1935) an American mineralogist, collector, and mineral dealer. Bixby explored the Thomas Range in Utah and staked several claims of Topaz, and he discovered Bixbyite there.
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Boehmite, also spelled as B hmite, is one of the three component minerals of the econ... More
Boehmite, also spelled as Böhmite, is one of the three component minerals of the economically important aluminum ore Bauxite. It is named after German mineralogist Johann Böhm. Hide
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div Boleite is a highly attractive, though uncommon, blue mineral that forms in very ... More
Boleite is a highly attractive, though uncommon, blue mineral that forms in very distinct crystal habits. Its crystals can be perfectly cubic, both in individual isolated crystals, and may be perched on fragile matrix. Boleite may also form together with the minerals Pseudoboleite and Cumengeite as epitaxial overgrowths, in mineralogically fascinating examples. These similar minerals form together in a single specimen with an inner cubic core of Boleite, and outer protruding portions either Pseudoboleite (additional protruding square faces) or Cumengeite (triangular faces in a star-like formation.)
Boleite has been found in several localities worldwide, however, its only significant source was the the Amelia Mine in Baja California, Mexico. To date, this is the only only locality that had produced this mineral in large, well-formed crystals, as well as the uncommon epitaxial overgrowths.
The matrix of Boleite crystals is often friable and can crumble. Matrix specimens are often stabilized with glue to prevent their crumbling. Boleite is named after its type locality at Boleo, Baja California, Mexico.
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div Boracite describes both a mineral group as well as an individual mineral within t... More
Boracite describes both a mineral group as well as an individual mineral within that group. The Boracite group is a solid solution series of chloro- borates, with Boracite, Chambersite, and Ericaite, as the main members. Boracite is the magnesium-rich end member, and the most prevalent mineral of this group.
Boracite is known for its equidimensional crystals, which may form in unique habits not seen elsewhere in the mineral kingdom. Up until recently, Boracite crystals were generally isolated small crystals, but a find in the Boulby Mine in England has produced large crystal groups much different then previous discoveries of this mineral. Boracite is named after its membership within the borate group, containing the element boron in its chemical composition.
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Borax occurs in arid regions, forming from evaporation of saline lake s. Borax is als... More
Borax occurs in arid regions, forming from evaporation of saline lakes. Borax is also synthetically formed as a by-product of mining operations of borate deposits, and most of the specimens from the famous mine at Boron, California, are formed this way. The first Borax specimens came several dry lake deposits in Tibet. They were shipped in large quantities by ancient caravans for profit. Much greater deposits were later found in the southwestern U.S., from which most of the world's industrial borax comes.
Borax specimens are translucent when fresh, but eventually lose water in their chemical structure and turn opaque, developing a white powder on their surfaces. If allowed to dehydrate, they will eventually crumble into a white powder. Because of this property, known as efflorescence, Borax is not commonly seen in collections. When a Borax specimen loses water, it alters into a new mineral called Tincalconite, which contains the same elements as Borax but has half the water, and crystallizes in a different crystal system.
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Bornite is an ore mineral of copper, and is known for its iridescent tarnish . nbsp P... More
Bornite is an ore mineral of copper, and is known for its iridescent tarnish. " Peacock Ore", which is sold to amateur mineral collectors and tourists, is often labeled as a variety of Bornite. However, most Peacock Ore in reality is Chalcopyrite treated with acid, which produces a strongly-colored iridescent tarnish. Bornite is named for Ignatius von Born, an Austrian mineralogist and paleontologist. Hide
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div Boulangerite typically forms in a unique crystal habit of fine acicular crystals ... More
Boulangerite typically forms in a unique crystal habit of fine acicular crystals that appear as woven, hair-like fibers. The thin fibers, which can be very thick covering an entire specimen, or thinly spaced on a matrix, are often bent or interwoven due to their flexibility. Boulangerite also forms as dense, hairy inclusions within other crystals, especially Calcite and Quartz. Boulangerite often forms together with the chemically similar mineral Jamesonite, and may be very difficult to visually distinguish from it. Boulangerite is named after Charles Louis Boulanger (1810-1849), a French mining engineer.
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div Bournonite has the distinction of being known as cogwheel ore , due to the unique... More
Bournonite has the distinction of being known as "cogwheel ore", due to the unique twinning habit where crystals form in a rough cruciform form with pitted, deeply striated edges. The early German miners called this mineral "radelerz" or wheel ore, describing the cogwheel habit. Bournonite can be very lustrous, with a bright metallic luster, though it sometimes develops a dulling tarnish.
Bournonite was positively identified in 1804 by French
mineralogist and crystallographer Count Jacques Louis de Bournon (1751–1825), founder of the
Geological Society of London. The name given by Bournon for this mineral was
Endellione (later Endellionite), after the Cornish locality where it was first described, but subsequently the name was changed
to Bournonite in Bournon's honor.
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Brochantite always occurs in an intensely deep green color. It is almost exclusively ... More
Brochantite always occurs in an intensely deep green color. It is almost exclusively in groups of small radiating needles, and often found together with the similar mineral Cyanotrichite, which has a deep blue color. The combination of bright green Brochantite and bright blue Cyanotrichite creates a beautiful and contrasting specimen when found together.
Brochantite was named in honor of French mineralogist and geologist André-Jean-François-Marie Brochant de Villiers (1772-1840). Brochant de Villiers was a professor of geology and mineralogy in the École des Mines in France, as well as its first pupil.
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div Bromargyrite is an ore of silver, and is very similar to Chlorargyrite , with whi... More
Bromargyrite is an ore of silver, and is very similar to Chlorargyrite, with which it forms a solid solution series. Bromargyrite contains the halogen bromine combined with silver, whereas Chlorargyrite contains chlorine with silver. Bromargyrite and Chlorargyrite can be visually indistinguishable from one another, and will often form in the same deposits. The intermediary mineral of this series, known as Embolite, is usually classified as a bromine-rich variety of Chlorargyrite. Bromargyrite and Chlorargyrite are also chemically similar to the rare mineral Iodargyrite, which has iodine in place of the bromine/chlorine.
Bromargyrite is named after its chemical composition: "brom" for bromine, and "argyros" for the Greek word used for silver.
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Brookite is one of the three main forms of titanium dioxide. It forms distinct and un... More
Brookite is one of the three main forms of titanium dioxide. It forms distinct and unique crystals, and is often associated with the two other minerals it is polymorphous with, Rutile and Anatase. Brookite almost always forms together with Quartz, and is occasionally entirely included within a Quartz crystal. Brookite is named in honor of Henry J. Brooke (1771-1857), an English mineralogist who specialized in crystallography and discovered several new mineral species. Hide
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div Brucite is most often in crude, uninteresting form, but several localities produc... More
Brucite is most often in crude, uninteresting form, but several localities produce distinct and interesting crystals which are highly desirable to collectors. Brucite may form as a standalone mineral, but it can also form as layers within minerals of the chlorite group and clay minerals such as Montmorillonite and Smectite. It forms a component of certain types of marbles, which are commercially known as pearl grey marble. Brucite is named in honor of Archibald Bruce (1777-1818), a mineralogist who first described this mineral.
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Buergerite is a rare member of the Tourmaline group. It was first discovered in 1966,... More
Buergerite is a rare member of the Tourmaline group. It was first discovered in 1966, and its locality was subsequently forgotten until the noted Mexican mineral collector Dr. Miguel Romero hired two exploration geologists to search and find the deposit. Subsequent finds have yielded very little material, and good specimens of this rare form of Tourmaline remain difficult to obtain. Buergerite is named in honor of Martin J. Buerger (1903-1986), a prominent mineralogist and professor of mineralogy at Massachusetts Institute of Technology. Hide
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Bustamite is an intermediary mineral between the Rhodonite and Wollastonite series . ... More
Bustamite is an intermediary mineral between the Rhodonite and Wollastonite series. It is often regarded as a calcium-rich variety of Rhodonite, but scientifically it is classified as an individual mineral, not a variety. It is very similar in habit to Rhodonite, and often forms in the same localities. However, its color is usually less intense red than that of Rhodonite, most often having a light pastel pink or brownish-red color. Bustamite was named in honor of Mexican general Anastasio Bustamente (1780-1853). Hide
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Bytownite is a rarer form of feldspar , more commonly seen as a facet ed gemstone the... More
Bytownite is a rarer form of feldspar, more commonly seen as a faceted gemstone then as a collectors mineral. It is usually translucent without a crystal form. Some other forms of feldspar, especially the transparent yellow form of Orthoclase, are faceted and incorrectly labeled as Bytownite. Bytownite belongs to the Plagioclase Feldspar group, an
isomorphous solid solution series. Albite is one member,
containing sodium and no calcium. The other end member, Anorthite,
contains calcium and no sodium. Bytownite is an intermediary
member of this series. Bytownite is considered by some authorities as a
variety of Anorthite rather then a separate mineral. The acclaimed
Dana's System of
Mineralogy lists Bytownite as an individual mineral,
whereas the IMA does not recognize it as individual mineral
species, but rather a sodium-rich variety of Anorthite. Hide
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