Quartz Varieties Visible Spectra (generally 350 - 1100 nm)

Images of the spectra of representative varieties

• Amethyst spectrum; Amethyst, Anahí Mine, Bolivia. Data Files: Amethyst. Amethyst color  develops in iron- containing quartz after exposure to ionizing radiation. More information is available on our ametrine page.

• Carnelian spectrum; Carnelian, unspecified locality. Data Files: Carnelian.

• Chrysoprase spectrum; Chrysoprase, Tulare County, California. Data Files: Chrysoprase 17884. The color of chrysoprase is due to minute inclusions of a Ni²⁺ layer silcate in the silica. In the case of the Australian chrysoprase, the nickel silicate is a member of the talc group which been identified both as willemseite, (Ni,Mg)₃Si₄O₁₀(OH)₂ and as kerolite, a variety of talc with a randomly stacked structure, in the series, kerolite - nickel-kerolite

• Citrine spectrum; Citrine = heated amethyst, GRR 3910, from Rio Grande do Sul, Brazil. 2.29 mm thick. The color  is due to small aggregrates of iron oxide.  

• Red jasper spectrum; Jasper, red, Crab lake, Labrador, colored by hematite. This is a reflectance spectrum off a polished slab. Data Files: Red jasper. The color comes from small inclusions of hematite, Fe₂O₃, in the quartz.
• Orange-brown jasper spectrum; Jasper, orange-brown, California. This is a reflectance spectrum off a polished slab. Data Files: Orange-brown jasper

• Rose quartz spectrum; Rose quartz, Ramshorn gulch, Tobacco Root Mountains, Montana. This is a diffuse reflectance spectrum. Data Files: GRR 1787. The color comes from minute fibers of an aluminum borosilicate phase contained in the quartz.
• Pink quartz spectrum. Crystal from Mount Mica, Maine, USA, 3.68 mm thick. Data Files: E perp c; E \\c. The color of the pink quartz  variety comes from P substutition in the silica. The quartz must be irradiated by natural gamma rays to strip an electron from the oxygen adjacent to the phosphorous presumably to form an O^- group. Synthetic pink quartz has also been produced. A 3.12 mm thick Russian synthetic crystal has essentially the same optical spectrum as its natural counterpart

• Smoky quartz spectrum: Smoky Quartz, Saline Valley, California.  15.5 mm thick crystal. The color of smoky quartz is due to radiation-induced color centers. One of the most prominent is centered on aluminum ions that replace silicon in the tetrahedral site.
• Smoky quartz spectrum: Smoky Quartz, Crystal Peak, Teller County, Colorado. 5.79 mm thick slice from a dark black crystal. Data Files:  E perpendicular to c;  E parallel to c. 

Link to an extensive collection of references to mostly color and visible spectroscopy of quartz

 Back to the Index of Data Files