Changbaiite
Encyclopedia
Changbaiite is a member of the oxide mineral
class in which the mineral contains oxygen
grouped with one or two metal ion. Changbaiite is classified as a multiple Oxide
XY2O6 and it generally have ionic bond
. Furthermore, it is also orthorhombic at a temperature of 25 degrees and it changes to orthorhombic-tetragonal at 570 degrees.
analysis of kaolinite
-filled veins. It is composed of iron (II) oxide FeO 0.94%, lead oxide
PbO 41.51%, iron (III) oxide Fe2O3 0.42%, titanium dioxide
TiO2 0.95%, niobium pentoxide
Nb2O5 55.62%, and tantalum pentoxide Ta2O5 0.98%, which produce the chemical formula (Pb0.95Fe2+0.05)(Nb1.95Ti0.05Fe3+0.02Ta0.01) or PbNb2O6. It was also examined by the spectrographic method which represents Sb 0.3, Si 0.1, Ba 0.2, Ca 0.1, and minor traces of copper
, magnesium
and aluminum.
Subbarao suggested that Changbaiite formula PbNb2O6 can vary. He represented lead niobate by A1+xNb2O6 where the A site is an ion (usually lead
) and he found that the upper limit of x in his representation was about 0.15 and a low limit between -0.07 and -0.08.in conclusion, the formula ranges from Pb0.92Nb2O6 to Pb1.15Nb2O6.
cavities and potassic granite
, which can be found in Tonghua
, Southeastern Kirin
, China
. Changbaiite was named after Changbai
Mountain in China
because it was found there.
of 8 around oxygen
. and the "tunnels" have a coordination of 10 around the Pb2+.
and is bounded, in sequence of lessening prominence. Normally it is colorless or sometimes appears in different schemes of colors like cream white, pale brown, yellowish-brown, pale yellowish-green with white streak
s and adamantine
to pearly luster
.
Changbaiite is nonmagnetic and breakable. Also, it possesses dual quality of translucent to transparent
. It has perfect basal cleavage
and distinct rhombohedral cleavage with hackly fracture
, on the other side spherulitic grains are conchoidal. Ultraviolet
light and cathode rays have no fluorescent effect on changbaiite and this is not soluble in hydrochloric acid
, nitric acid
or sulphuric acid but conditionally less soluble in hot phosphoric acid
.. Changbaiite has a hardness of 472.4 kg/mm2 on the Vickers hardness scale and 5.3 on mohs scale. In a optical spectrum
changbaiite is uniaxial positive and it can be biaxial. Changbaiite reflectance, which is the fraction of incident radiation
reflected by a surface, is 15.86 at 546 nm.
-constant capacitors and the development of piezoelectric transducers. In the medical field, ferroelectric minerals helped in developing the ultrasonic
composite. Ferroelectric minerals are the main cause of many successful industries with high revenues.
Oxide mineral
The oxide mineral class includes those minerals in which the oxide anion is bonded to one or more metal ions. The hydroxide bearing minerals are typically included in the oxide class...
class in which the mineral contains oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
grouped with one or two metal ion. Changbaiite is classified as a multiple Oxide
Oxide
An oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
XY2O6 and it generally have ionic bond
Ionic bond
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. Pure ionic bonding cannot exist: all ionic compounds have some...
. Furthermore, it is also orthorhombic at a temperature of 25 degrees and it changes to orthorhombic-tetragonal at 570 degrees.
Composition
The chemical formula of changbaiite is PbNb2O6 after microprobeMicroprobe
A microprobe is an instrument that applies a stable and well-focused beam of charged particles to a sample.-Types:When the primary beam consists of accelerated electrons, the probe is termed an electron microprobe, when the primary beam consists of accelerated ions, the term Ion Microprobe is used...
analysis of kaolinite
Kaolinite
Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O54. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra...
-filled veins. It is composed of iron (II) oxide FeO 0.94%, lead oxide
Lead(II) oxide
Lead oxide is the inorganic compound with the formula PbO. Lead oxide occurs in two polymorphs, red, having a tetragonal crystal structure and yellow, having an orthorhombic crystal structure...
PbO 41.51%, iron (III) oxide Fe2O3 0.42%, titanium dioxide
Titanium dioxide
Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
TiO2 0.95%, niobium pentoxide
Niobium pentoxide
Niobium pentoxide is the inorganic compound with the formula Nb2O5. It is a colourless insoluble solid that is fairly unreactive. It is the main precursor to all materials made of niobium, the dominant application being alloys, but other specialized applications include capacitors, lithium niobate,...
Nb2O5 55.62%, and tantalum pentoxide Ta2O5 0.98%, which produce the chemical formula (Pb0.95Fe2+0.05)(Nb1.95Ti0.05Fe3+0.02Ta0.01) or PbNb2O6. It was also examined by the spectrographic method which represents Sb 0.3, Si 0.1, Ba 0.2, Ca 0.1, and minor traces of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
and aluminum.
Subbarao suggested that Changbaiite formula PbNb2O6 can vary. He represented lead niobate by A1+xNb2O6 where the A site is an ion (usually lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
) and he found that the upper limit of x in his representation was about 0.15 and a low limit between -0.07 and -0.08.in conclusion, the formula ranges from Pb0.92Nb2O6 to Pb1.15Nb2O6.
Geological occurrence
Changbaiite can be found in kaoliniteKaolinite
Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O54. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra...
cavities and potassic granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
, which can be found in Tonghua
Tonghua
-Economy:Traditionally, Tonghua occupied a railhub position in a region of China noted for trade in only three agricultural commodities. These were ginseng, marten furs and deer antler products. In the 1980s Tonghua had some success with a wine distillery producing sweet, sticky red wines that...
, Southeastern Kirin
Jilin
Jilin , is a province of the People's Republic of China located in the northeastern part of the country. Jilin borders North Korea and Russia to the east, Heilongjiang to the north, Liaoning to the south, and Inner Mongolia to the west...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. Changbaiite was named after Changbai
Changbai Mountains
The Changbai Mountain Range or Jangbaek Mountain Range are a mountain range on the border between China and North Korea...
Mountain in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
because it was found there.
Atomic structure
According to Subbarao changbaiite is orthorhombic at 25°C with unit cell dimensions of a=17.65, b=17.91, c=7.736 angstrom and because its big unit cell size it's difficult to do a full structure analysis of PbNb2O6. Changbaiite structure is composed of NbO6 octahedral crystals connected at their corners forming circles of 3 to 5 octahedral. The NbO6 "cage" has coordinationCoordination number
In chemistry and crystallography, the coordination number of a central atom in a molecule or crystal is the number of its nearest neighbours. This number is determined somewhat differently for molecules and for crystals....
of 8 around oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
. and the "tunnels" have a coordination of 10 around the Pb2+.
Physical properties
Changbaiite has a trigonal crystal system and a space group of R3m. Its lattice dimensions are a= 10.499A c = 11.553A. Changbaiite can be found as a small crystal with a tabular or spherules crystal shape. It can get up to 5mm in size and averages from 0.2 to 0.4mm. Changbaiite’s trigonal crystals show 3m symmetrySymmetry
Symmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection...
and is bounded, in sequence of lessening prominence. Normally it is colorless or sometimes appears in different schemes of colors like cream white, pale brown, yellowish-brown, pale yellowish-green with white streak
Streak (mineralogy)
The streak of a mineral is the color of the powder produced when it is dragged across an unweathered surface. Unlike the apparent color of a mineral, which for most minerals can vary considerably, the trail of finely ground powder generally has a more consistent characteristic color, and is thus...
s and adamantine
Lustre (mineralogy)
Lustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. The word lustre traces its origins back to the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance....
to pearly luster
Lustre (mineralogy)
Lustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. The word lustre traces its origins back to the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance....
.
Changbaiite is nonmagnetic and breakable. Also, it possesses dual quality of translucent to transparent
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...
. It has perfect basal cleavage
Cleavage (crystal)
Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the...
and distinct rhombohedral cleavage with hackly fracture
Fracture
A fracture is the separation of an object or material into two, or more, pieces under the action of stress.The word fracture is often applied to bones of living creatures , or to crystals or crystalline materials, such as gemstones or metal...
, on the other side spherulitic grains are conchoidal. Ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
light and cathode rays have no fluorescent effect on changbaiite and this is not soluble in hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
, nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
or sulphuric acid but conditionally less soluble in hot phosphoric acid
Phosphoric acid
Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...
.. Changbaiite has a hardness of 472.4 kg/mm2 on the Vickers hardness scale and 5.3 on mohs scale. In a optical spectrum
Spectrum
A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...
changbaiite is uniaxial positive and it can be biaxial. Changbaiite reflectance, which is the fraction of incident radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
reflected by a surface, is 15.86 at 546 nm.
Special characteristics
Changbaiite is considered to be a ferroelectric mineral. Ferroelectric minerals helped in the development of high-dielectricDielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
-constant capacitors and the development of piezoelectric transducers. In the medical field, ferroelectric minerals helped in developing the ultrasonic
Ultrasonic sensor
Ultrasonic sensors work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor...
composite. Ferroelectric minerals are the main cause of many successful industries with high revenues.