|
*St. Benedict GARNET GEMSTONE Bead gift Rosary Catholic Necklace Cross Jerusalem |
|
*St. Benedict GARNET GEMSTONE Bead gift Rosary Catholic Necklace Cross Jerusalem
Beads Size: 6 mm
Crucifix Size: 4.5cm
Medal : 2.0cm
Rosary: 70 cm Length from the cross to the end
Garnet
Garnet
is a group of minerals that have been used since the Bronze Age as
gemstones and abrasives. Garnets are most often seen in red, but are
available in a wide variety of colors spanning the entire spectrum. The
name "garnet" comes from the Latin granatus ("grain"), possibly a
reference to the Punica granatum ("pomegranate"), a plant with red seeds
similar in shape, size, and color to some garnet crystals.
Six
common species of garnet are recognized based on their chemical
composition. They are pyrope, almandine, spessartite, grossular
(varieties of which are hessonite or cinnamon-stone and tsavorite),
uvarovite and andradite. The garnets make up two solid solution series;
1. pyrope-almandine-spessarite and
2. uvarovite-grossular-andradite.
Physical Properties
Garnets
species are found in many colors including red, orange, yellow, green,
blue, purple, brown, black, pink and colorless. The rarest of these is
the blue garnet, discovered in the late 1990s in Bekily, Madagascar. It
is also found in parts of the United States, Russia and Turkey. It
changes color from blue-green in the daylight to purple in incandescent
light, as a result of the relatively high amounts of vanadium (about 1
wt.% V2O3). Other varieties of color-changing garnets exist. In
daylight, their color ranges from shades of green, beige, brown, gray,
and blue, but in incandescent light, they appear a reddish or
purplish/pink color. Because of their color changing quality, this kind
of garnet is often mistaken for Alexandrite.
Garnet
species's light transmission properties can range from the
gemstone-quality transparent specimens to the opaque varieties used for
industrial purposes as abrasives. The mineral's luster is categorized as
vitreous (glass-like) or resinous (amber-like).
Crystal Structure
Garnets
are nesosilicates having the general formula X3Y2(SiO4)3. The X site is
usually occupied by divalent cations (Ca2+, Mg2+, Fe2+) and the Y site
by trivalent cations (Al3+, Fe3+, Cr3+) in an octahedral/tetrahedral
framework with [SiO4]4− providing the tetrahedra[2]. Garnets are most
often found in the dodecahedral crystal habit, but are also commonly
found in the trapezohedron habit. (Note: the word "trapezohedron" as
used here and in most mineral texts refers to the shape called a
Deltoidal icositetrahedron in solid geometry.) They crystallize in the
isometric system, having three axes that are all of equal length and
perpendicular to each other. Garnets do not show cleavage, so when they
fracture under stress, sharp irregular pieces are formed
Hardness
Because
the chemical composition of garnet varies, the atomic bonds in some
species are stronger than in others. As a result, this mineral group
shows a range of hardness on the Mohs Scale of about 6.5 to 7.5. The
harder species, like almandine, are often used for abrasive purposes.
Garnet group endmember species
Almandine,
sometimes incorrectly called almandite, is the modern gem known as
carbuncle (though originally almost any red gemstone was known by this
name). The term "carbuncle" is derived from the Latin meaning "little
spark." The name Almandine is a corruption of Alabanda, a region in Asia
Minor where these stones were cut in ancient times. Chemically,
almandine is an iron-aluminium garnet with the formula Fe3Al2(SiO4)3;
the deep red transparent stones are often called precious garnet and are
used as gemstones (being the most common of the gem garnets). Almandine
occurs in metamorphic rocks like mica schists, associated with minerals
such as staurolite, kyanite, andalusite, and others. Almandine has
nicknames of Oriental garnet, almandine ruby, and carbuncle.
Pyrope
(from the Greek pyropós meaning "fire-eyed") is red in color and
chemically a magnesium aluminium silicate with the formula
Mg3Al2(SiO4)3, though the magnesium can be replaced in part by calcium
and ferrous iron. The color of pyrope varies from deep red to almost
black. Transparent pyropes are used as gemstones.
A
variety of pyrope from Macon County, North Carolina is a violet-red
shade and has been called rhodolite, from the Greek meaning "a rose." In
chemical composition it may be considered as essentially an isomorphous
mixture of pyrope and almandite, in the proportion of two parts pyrope
to one part almandite. Pyrope has tradenames some of which are
misnomers; Cape ruby, Arizona ruby, California ruby, Rocky Mountain
ruby, and Bohemian garnet from the Czech Republic. Another intriguing
find is the blue color-change garnets from Madagascar, a pyrope
spessartine mix. The color of these blue garnets is not like sapphire
blue in subdued daylight but more reminiscent of the grayish blues and
greenish blues sometimes seen in spinel However in white LED light the
color is equal to the best corn flower blue sapphire or D block
tanzanite this is due to the blue garnets ability to absorb the yellow
component of the emitted light.
Pyrope
is an indicator mineral for high pressure rocks. The garnets from
mantle derived rocks, peridotites and eclogites, commonly contain a
pyrope variety.
Spessartine
or incorrectly spessartite is manganese aluminium garnet,
Mn3Al2(SiO4)3. Its name is derived from Spessart in Bavaria. It occurs
most often in granite pegmatite and allied rock types and in certain low
grade metamorphic phyllites. Spessartine of a beautiful orange-yellow
is found in Madagascar (see Mandarin garnet). Violet-red spessartines
are found in rhyolites in Colorado and Maine.
Andradite
is a calcium-iron garnet, Ca3Fe2(SiO4)3, is of variable composition and
may be red, yellow, brown, green or black. The recognized varieties are
topazolite (yellow or green), demantoid (green) and melantite (black).
Andradite is found both in deep-seated igneous rocks like syenite as
well as serpentines, schists, and crystalline limestone. Demantoid has
been called the "emerald of the Urals" from its occurrence there, and is
one of the most prized of garnet varieties. Topazolite is a golden
yellow variety and melanite is a black variety.
Grossular
is a calcium-aluminium garnet with the formula Ca3Al2(SiO4)3, though
the calcium may in part be replaced by ferrous iron and the aluminium by
ferric iron. The name grossular is derived from the botanical name for
the gooseberry, grossularia, in reference to the green garnet of this
composition that is found in Siberia. Other shades include cinnamon
brown (cinnamon stone variety), red, and yellow. Because of its inferior
hardness to zircon, which the yellow crystals resemble, they have also
been called hessonite from the Greek meaning inferior. Grossular is
found in contact metamorphosed limestones with vesuvianite, diopside,
wollastonite and wernerite.
One
of the most sought after varieties of gem garnet is the fine green
grossular garnet from Kenya and Tanzania called tsavorite. This garnet
was discovered in the 1960s in the Tsavo area of Kenya, from which the
gem takes its name.
Uvarovite
is a calcium chromium garnet with the formula Ca3Cr2(SiO4)3. This is a
rather rare garnet, bright green in color, usually found as small
crystals associated with chromite in peridotite, serpentinite, and
kimberlites. It is found in crystalline marbles and schists in the Ural
mountains of Russia and Outokumpu, Finland.
Geological importance of garnet
The
Garnet group is a key mineral in interpreting the genesis of many
igneous and metamorphic rocks via geothermobarometry. Diffusion of
elements is relatively slow in garnet compared to rates in many other
minerals, and garnets are also relatively resistant to alteration.
Hence, individual garnets commonly preserve compositional zonations that
are used to interpret the temperature-time histories of the rocks in
which they grew. Garnet grains that lack compositional zonation commonly
are interpreted as having been homogenized by diffusion, and the
inferred homogenization also has implications for the temperature-time
history of the host rock.
Garnets
are also useful in defining metamorphic facies of rocks. For instance,
eclogite can be defined as a rock of basalt composition, but mainly
consisting of garnet and omphacite. Pyrope-rich garnet is restricted to
relatively high-pressure metamorphic rocks, such as those in the lower
crust and in the Earth's mantle. Peridotite may contain plagioclase, or
aluminum-rich spinel, or pyrope-rich garnet, and the presence of each of
the three minerals defines a pressure-temperature range in which the
mineral could equilibrate with olivine plus pyroxene: the three are
listed in order of increasing pressure for stability of the peridotite
mineral assemblage. Hence, garnet peridotite must have been formed at
great depth in the earth. Xenoliths of garnet peridotite have been
carried up from depths of 100 km and greater by kimberlite, and garnets
from such disaggegated xenoliths are used as a kimberlite indicator
minerals in diamond prospecting. At depths of about 300 to 400 km and
greater, a pyroxene component is dissolved in garnet, by the
substitution of (Mg,Fe) plus Si for 2Al in the octahedral (Y) site in
the garnet structure, creating unusually silica-rich garnets that have
solid solution towards Majorite. Such silica-rich garnets have been
identified as inclusions within diamonds.
Uses of garnets
Pure
crystals of garnet are used as gemstones. Garnet sand is a good
abrasive, and a common replacement for silica sand in sand blasting.
Mixed with very high pressure water, garnet is used to cut steel and
other materials in water jets. Garnet sand is also used for water
filtration media.
* In the USA it is known as the birthstone for January.
* It is the gemstone for the 2nd wedding anniversary
* It is the state mineral of Connecticut.
* It is also New York's gemstone.
I'm sorry due to the limit of my camera, I cannot present the complete beauty of this bead to you. If you have the chance to get this Rosary, please don't forget to admire it under light.This Rosary will become part of your life! If you have any questions or you need more information about this or any other product, please email me.Please take a moment to browse through the other lovely jewelry items in my store, and add me to your list of favorites.
Posting Despatch: I normally post within 1 working days of receiving payment and the delivery time is about 3-12 business days (I consider extra time just in case...), the beautiful item posted to you from Tibet or Shanghai. 1. Choose a Airmail postage option for your package: Estimated delivery time is 6 - 12 Days ( business Days) US$ 6.95.to United State. 2. Choose a EMS postage option for your package: Estimated delivery time is 3 - 6 Days ( business Days) US$ 20.99.to United State. If you need something urgently, please contact me before.
Thoughts about combine shipping: If you wish to combine few items together in one shipping, please contact me before.Usually I give discounts for a few items shippings. If you wish to combine few items together in one shipping, please contact me before.Usually I give discounts for a few items shippings. Unexpected problems & further information: If you have any Unexpected problems with the product, Please contact me before you hurry to use the negative feedback and I promiss to deal with the situation for your satisfaction.If you have any Unexpected problems with the product, Please contact me before you hurry to use the negative feedback and I promiss to deal with the situation for your satisfaction.
Refunds & Returns: I'm happy to accept Returns, but the item MUST be returned first.If you need to return your item, please let me know via email and return the item in original condition.
Terms of Payment: I am use and recommend payment through PayPal, the fast, Payment should be received within 5 days from the date of your final purchase and cannot guarantee an item to be available if payment arrives after this time. I am deliver to: USA CANADA MEXICO EUROPE.
| | | |
|