Thursday, April 16, 2015

Difference between Rose Quartz and Pink Quartz

Rose Quartz is the rosy pink variety of Quartz. Its color is usually soft, ranging from very light pink to medium pink in intensity and lack good transparency. It is never transparent, and it does not form single crystals. Rose quartz is usually very evenly colored.  Rose quartz is slightly to highly turbid, indicating the presence of the second phase, namely pink-colored fibrous inclusions [3] [4].
Quartz single crystals of a similar rose color are called pink quartz. The single-crystal pink quartz is photochemically unstable, unlike massive rose quartz, it is extremely rare.
Based on their optical properties and chemical composition, these two types of quartz appears to be of a different nature: (1) the cause of their color is different, (2) pink quartz is sensitive to light, while rose quartz is not, (3) both varieties form in different environments, and (4) pink quartz develops single crystals while rose quartz does not.
In spite of extensive studies over the last century, the source of the rose coloration in quartz still remains a subject of active debate. Many possible mechanisms for the color of rose quartz have been proposed [1], but no consensus has developed. More recently it has been suggested [3] that fibrous inclusions are responsible for color of rose quartz. The nature of the colorizing nanofibers in rose quartz has recently been studied [4], following the more "direct" approach that was already chosen [3], they dissolved rose quartz from various locations in hydrofluoric acid and extracted mats of visually homogeneous, fine textured, flaky pink-colored nanofibers.  The fibrous mineral inclusions are rose-colored mineral and could be a mixture of dumortierite and a related phase. The mineral makes up only about 0.05% - 0.15% of the overall weight of rose quartz. The mineral will bleach when heated above 500°C, but will not regain its color when irradiated. Color loss can be induced by oxidizing agents, too, and heat treatment in a reducing atmosphere will turn heated and paled material rose-colored again.  Experiments also show the embedded mineral fibers are not randomly oriented, but preferrably oriented along specific crystallographic axes.  Thus pink-colored fibrous inclusions cause the coloration of rose quartz.
Pink quartz’s color is caused by small amounts of aluminum, Al(+3), and phosphorus, P(+5), built pairwise into the crystal lattice to replace Si(+4), and subsequent high energy irradiation [1]. The two electrically neutral SiO4 groups are replaced by one AlO4- and one PO4+ group. Pink quartz is often accompanied by phosphate minerals, like (Mn,Fe)Al[(OH)2|PO4]•H2O.  Many pink quartz is translucent to transparent. Pink quartz is very sensitive to light and will pale quickly in direct sunlight. This is an indication that the color is due to color centers whose formation appears to be triggered by high energy radiation.
Rose quartz occurs at many pegmatite locations all over the world. It is commercially mined in Madagascar, South-Africa, Namibia, U.S.A. (South Dakota), and Brazil (Bahia and Minas Gerais). Star rose quartz is found in South Dakota and Madagascar. Pink quartz was first found in Brazil in 1959 which is still the main source.
Pink Quartz is an extremely rare single crystal and usually cut to make gemstone beads for ring and pendant. Rose Quartz is an affordable gemstone, and is used in various form of jewelry. Rose Quartz is most often used in beads with different shapes:  round, coin, oval, square, pillow, cube, tube, et al. With Rose Quartz beads in your favorite color and shape, you even can create your own unique piece of Rose Quartz jewelry, and with plenty of opportunity to customize to fit your unique style. There are plenty of low-cost Rose Quartz beads available through online store and be sure to check out the discounted Rose Quartz beads first to start your design.
The fact that Pink Quartz can lose its color makes it obvious that Pink Quartz jewelry should not be worn while sunbathing. High temperature can be harmful to the Rose Quartz.
Reference:

[1] G.R. Rossman, “Colored varieties of the silica minerals”, Reviews in Mineralogy, Vol.29 
[2] Maschmeyer, D., Lehmann, G. (1983) A trapped-hole center causing rose coloration of natural quartz. Zeitschrift für Kristallographie, 163: 181-186.
[3] Applin, K.R., Hicks, B.D. (1987) Fibers of dumortierite in quartz. American Mineralogist, 72, 170-172
[4] Goreva, J.S., Ma, C., Rossman, G.R. (2001) Fibrous nanoinclusions in massive rose quartz: The origin of rose coloration. American Mineralogist, 86: 466-471.


[5] Hori, H. (2001) Nomenclature of Quartz Color Variation: Pink and Rose. Mineralogical Record, 32(1). 

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