Where is Tourmalinated Quartz found?
SiO2 with (Na,Ca)(Mg,Fe,Li,Al)3Al6(BO3)3Si6O18(OH)4
Got a photo? Identify rocks instantly with the Rockby app
Open the appTourmalinated Quartz occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Tourmalinated Quartz
Brazil
Minas Gerais is a prolific source of high-quality tourmalinated quartz, particularly with clear quartz and well-formed black tourmaline needles.
United States
Localities in Maine, California (San Diego County), and North Carolina are known for tourmaline-bearing pegmatites, which can yield tourmalinated quartz.
Madagascar
Known for various tourmaline varieties and quartz, often found together in pegmatitic environments.
Pakistan
Certain regions produce quartz with tourmaline inclusions, often from pegmatite deposits.
Collecting tips
- Geological Context. Focus your search in areas known for pegmatites, granitic intrusions, or hydrothermal vein systems. Look for outcrops of quartz veins or pegmatite dikes.
- Visual Identification. Look for clear, milky, or smoky quartz crystals or masses containing distinct, often black, needle-like or prismatic inclusions. The inclusions should have a vitreous luster and often exhibit characteristic striations.
- Hardness Test. Quartz (Mohs 7) will scratch glass. Tourmaline (Mohs 7-7.5) is slightly harder than quartz but will also scratch glass. This helps distinguish it from softer inclusions.
- Associated Minerals. Tourmalinated quartz is often found alongside other pegmatite minerals such as feldspar, mica, beryl, and other tourmaline varieties.
Quick Check
- Color:
- Quartz: colorless, white, gray, smoky. Tourmaline: typically black.
- Luster:
- Vitreous (glassy).
- Streak:
- White (for quartz); colorless (for tourmaline, though often not practical to streak inclusions).
Explore Tourmalinated Quartz
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.