What is Rose Quartz?
Rose quartz is the name used for pink specimens of the mineral quartz. It is abundant, common, and found in large quantities at numerous locations around the world. It is usually occurs as massive, anhedral occurrences in hydrothermal veins and pegmatites.
The pink color of rose quartz is attributed to microscopic inclusions of a pink variety of the mineral dumortierite. These inclusions are usually abundant enough to make the rose quartz translucent instead of transparent. 
Rarely, quartz occurs as transparent euhedral crystals with a pink color. These are usually late-stage mineralizations in pegmatite pockets. The color of these specimens, especially those that are transparent, is thought to be caused by irradiation-induced color centers. This color is often unstable, fading with exposure to heat or light. Pink transparent quartz is rare, but found in several locations around the world. Many people believe that pink transparent quartz should be called “pink quartz” instead of “rose quartz” because the cause of the color is different. 
Physical Properties of Rose Quartz
|Color||Pale pink to vivid pink. Sometimes zoned.|
|Streak||Colorless (harder than the streak plate)|
|Diaphaneity||Transparent to translucent|
|Cleavage||None, breaks with a conchoidal fracture|
|Specific Gravity||2.6 to 2.7|
|Diagnostic Properties||Conchoidal fracture, glassy luster, hardness, pink color, translucence|
|Uses||Cabochons, beads, carvings, spheres|
Physical Properties of Rose Quartz
The pink color of rose quartz ranges from a very light, almost imperceptible pink, to a rich translucent pink. It is usually cut into cabochons, beads, and faceted stones of about eight millimeters in size or larger to display the rich pink color.
Some specimens of rose quartz contain a dense network of fine inclusions that align with the gem’s hexagonal crystal structure. If a cabochon is cut so that its base is perpendicular to the c-axis of the quartz crystal, the cabochon might display asterism in the form of a six-ray star. The best star stones have a vivid pink color and a distinct, symmetrical, and well-centered star.
Uses of Rose Quartz
Rose quartz is one of the most commonly encountered lapidary materials. It is abundant, usually inexpensive, and popular as tumbled stones, beads, and cabochons. These have the richest color when pieces are at least a centimeter in diameter or thickness because of the material’s weak color. With a hardness of 7 on the Mohs scale and a lack of cleavage, rose quartz is durable enough for use in any type of jewelry.
Faceted rose quartz is rarely seen because transparent pink quartz is rare, and translucent rose quartz does not compete well with other faceted materials. Although rose quartz cabochons are popular in craft jewelry, rose quartz is seen far less often in commercial or designer jewelry. Its pink color does not contrast strongly with metal settings or the skin color of many people. Faceted gems such as pink sapphire, morganite, rhodolite, spinel, and tourmaline are used instead of pink quartz, probably because of their superior clarity and brighter luster.
Pieces of rose quartz up to a few pounds in size with nice color are usually available and relatively inexpensive. For that reason it is commonly used to produce small sculptures, puffed hearts, spheres, and utility items.
Color and Asterism in Rose Quartz
In the mineralogical literature, the pink color of rose quartz has been attributed to titanium, manganese, and iron by a large number of authors for over 100 years. Tiny needles of rutile have been given credit for forming the six-ray star of rose quartz for the same amount of time.
In the late 1990s, an interesting investigation into the color and asterism of rose quartz was done by George Rossman, Julia Goreva, and Chi Ma at Caltech . They obtained samples of rose quartz from a number of localities throughout the world and gently dissolved them in hydrofluoric acid heated to 100 degrees Celsius. This treatment was intended to dissolve away the silicon dioxide of the quartz and any included material soluble in HF at 100 degrees Celsius.
In specimen after specimen, a tangle of extremely thin pink fibers remained after the acid treatment. They examined these fibers using scanning electron microscopy, infrared spectroscopy, Raman spectroscopy, optical absorption spectroscopy, and x-ray diffraction. Through this they determined that the pink fibers are a borosilicate with properties that are very similar to those of dumortierite. These investigators believe that the pink color and asterism of rose quartz is caused by these pink fibers that they have named dididumortierite.
Sources, Treatments, and Synthetics
Rose quartz is found in abundance in many deposits throughout the world. Much of the rose quartz that is sold today is produced in Brazil, South Africa, India, and Madagascar. Other sources include Namibia, Mozambique, and Sri Lanka. In the United States, a deposit near Custer, South Dakota once produced significant amounts of rose quartz.
Rose quartz has been produced in laboratories, but synthetic rose quartz does not have a significant presence in the gem and jewelry marketplace. Natural material is too abundant, inexpensive, and only seen in craft jewelry. This removes the incentive to produce synthetic rose quartz instead of other, more highly priced materials.