Lising description
Rose quartz is one of the most desirable
varieties of quartz. The pink to rose red color is completely unique, unlike
any other pink mineral species. The color is caused by iron and titanium
impurities.
Detailed descrtion
Rose quartz is
one of the most desirable varieties of quartz. The pink to rose red color is
completely unique, unlike any other pink mineral species. The color is caused
by iron and titanium impurities.
Rose quartz is
used as an ornamental stone and as a gemstone. It is also an alternate birthstone for the month of January. Rose quartz
is associated with emotional balance and forgiveness.
Although rose
quartz is usually too cloudy to be used as a cut gemstone, a few exceptional
pieces are found with enough clarity and color to make fine gems. Most gemmy
rose quartz is used as cabochons where the clarity is not as important as the
color. Rose quartz is also a very attractive ornamental stone and is carved
into spheres, pyramids, obelisks, figurines and ornate statues.
Rose quartz is
found in Madagascar, India, Germany, and several localities in the USA. Much
rose quartz was extracted from a famous site near Custer, South Dakota, but
now, most of the worlds supply of good quality rose quartz comes from Brazil.
Brazil is also
the only current source of true well-formed crystals of rose quartz. Rose
quartz was once believed to be only massive, found primarily in the cores of
pegmatites. This lack of crystals is somewhat of a curiosity because quartz
crystallizes into well-formed crystals in all its other macroscopic varieties.
So amazing are the rose quartz crystals that the first ones discovered were
dismissed as fakes by mineralogists from around the world.
If rutile needles are present in the rose
quartz then a star effect or asterism is sometimes seen. The star is best seen
when light is viewed through the rose quartz. This is different from asterisms
in most other gemstones, such as ruby and sapphire, where the stars are seen when light
is shown on the gems.
Rose quartz is
only one of several quartz varieties. Other varieties that form macroscopic
(large enough to see) crystals are as follows:
- Amethyst is the
purple gemstone variety.
- Citrine is a yellow
to orange gemstone variety that is rare in nature but is often created by
heating Amethyst.
- Milky
Quartz
is the cloudy white variety.
- Prasiolite is the
leek-green variety.
- Rock
crystal
is the clear variety that is also used as a gemstone.
- Smoky
quartz
is the brown to gray variety.
Quartz is the second most abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous
framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared
between two tetrahedra, giving an overall formula SiO2.
There are many
different varieties of quartz, several of which are semi-precious gemstones. Especially in Europe and the Middle
East, varieties of quartz have been since antiquity the most commonly used
minerals in the making of jewelry and hardstone carvings.
The word
"quartz" is derived from the German word "quarz", which was
imported from Middle High German, "twarc", which originated in Slavic (cf. Czech tvrdy ("hard"),
Polish twardy ("hard"), Russian твёрдый ("hard")), from Old
Bulgarian (Church Slavonic) тврьдъ ("firm"), from Proto-Slavic
*tvьrdъ.[6]
Although all
quartz at temperatures lower than 573 °C is low quartz, there are a few
examples of crystals that obviously started out as β-quartz. Sometimes these
are labeled as β-quartz but are actually examples of pseudomorphic or
"falsely shaped" crystals more correctly labeled 'quartz after
β-quartz'. These crystals are of higher symmetry than low quartz although low
quartz can form similar crystals to them. They are composed of hexagonal
dipyramids which are a pair of opposing six sided pyramids and the crystals
lack prism faces. Quartz's typical termination is composed of two sets of three
rhombic faces that can look like a six sided pyramid.
(Microscopic) crystal structure
α-quartz
crystallizes in the trigonal crystal system, space group P3121
and P3221 respectively. β-quartz belongs to the hexagonal
system, space group P6221 and P6421,
respectively.[7] These spacegroups are truly chiral
(they each belong to the 11 enantiomorphous pairs). Both α-quartz and β-quartz
are examples of chiral crystal structures composed of achiral building blocks
(SiO4 tetrahedra in the present case). The transformation between α-
and β-quartz only involves a comparatively minor rotation of the tetrahedra
with respect to one another, without change in the way they are linked.
Varieties (according to color)
Pure quartz,
traditionally called rock crystal (sometimes called clear quartz),
is colorless and transparent
(clear) or translucent, and has often been used for hardstone carvings, such as the Lothair Crystal. Common colored varieties include
citrine, rose quartz, amethyst, smoky quartz, milky quartz, and
others. Quartz goes by an array of different names. The most important
distinction between types of quartz is that of macrocrystalline
(individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties (aggregates of crystals
visible only under high magnification). The cryptocrystalline varieties are
either translucent or mostly opaque, while the transparent varieties tend to be
macrocrystalline. Chalcedony is a cryptocrystalline form of silica
consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite.[8] Other opaque gemstone varieties of
quartz, or mixed rocks including quartz, often including contrasting bands or
patterns of color, are agate, sard, onyx, carnelian, heliotrope,
and jasper.
Citrine
Citrine is a variety of quartz whose color
ranges from a pale yellow to brown. Natural citrines are rare; most commercial
citrines are heat-treated amethysts or smoky quartzes. It is nearly impossible to tell cut
citrine from yellow topaz visibly, but they differ in hardness.
Citrine has ferric impurities, and is rarely found
naturally. Brazil is the leading producer of citrine,
with much of its production coming from the state of Rio Grande do Sul. The name is derived from Latin citrina which means
"yellow" and is also the origin of the word "citron." Sometimes
citrine and amethyst can be found together in the same crystal and is referred
to as ametrine.[9]
Rose quartz
Rose
quartz is a type of
quartz which exhibits a pale pink to rose red hue. The color is usually
considered as due to trace amounts of titanium, iron, or manganese, in the massive material. Some rose
quartz contains microscopic rutile needles which produces an asterism
in transmitted light. Recent X-ray diffraction studies suggest that the color is due
to thin microscopic fibers of possibly dumortierite within the massive quartz.[10]
In crystal form
(rarely found) it is called pink quartz and its color is thought to be
caused by trace amounts of phosphate or aluminium. The color in crystals is apparently
photosensitive and subject to fading. The first crystals were found in a pegmatite found near Rumford, Maine, USA, but most crystals on the market
come from Minas Gerais,
Brazil.[11]
Rose quartz is
not popular as a gem – it is generally too clouded by impurities to be suitable
for that purpose. Rose quartz is more often carved into figures such as people
or hearts. Hearts are commonly found because rose quartz is pink and an
affordable mineral.
Amethyst
Amethyst is a popular form of quartz that
ranges from a bright to dark or dull purple color.
Smoky quartz
Smoky
quartz is a gray,
translucent version of quartz. It ranges in clarity from almost complete
transparency to a brownish-gray crystal that is almost opaque. Some can also be
black.
Milky quartz
Milk
quartz or milky
quartz may be the most common variety of crystalline quartz and can be
found almost anywhere. The white color may be caused by minute fluid inclusions of gas, liquid, or both, trapped
during the crystal formation. The cloudiness caused by the inclusions
effectively bars its use in most optical and quality gemstone applications.[12]
Varieties (according to microstructure)
Although many of
the varietal names historically arose from the color of the mineral, current
scientific naming schemes refer primarily to the microstructure of the mineral.
Color is a secondary identifier for the cryptocrystalline minerals, although it
is a primary identifier for the macrocrystalline varieties. This does not
always hold true.
Synthetic and artificial treatments
Not all varieties
of quartz are naturally occurring. Prasiolite, an olive colored material, is
produced by heat treatment; natural prasiolite has also been observed in Lower
Silesia in Poland. Although citrine occurs naturally, the majority is the
result of heat-treated amethyst. Carnelian is widely heat-treated to deepen its
color.
Due to natural
quartz being so often twinned, much of the quartz used in industry
is synthesized. Large, flawless and untwinned crystals are produced in an autoclave via the hydrothermal process; emeralds are also synthesized in this fashion.
While these are still commonly referred to as quartz, the correct term for this
material is silicon dioxide.
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