Death Valley geology field trip All about Death Valley borax

Borax "cotton ball", made up of the hydrous borate minerals ulexite and proberite. Photo from NPS archives. Borax basics Uses for borax Death Valley borate minerals Borax basics Pure boron is never found in nature because of its strong attraction to oxygen. However, over 100 minerals, called borates, contain boron and oxygen (borate radical, BO) as important constituents. There are two basic types of borate minerals. The relatively rare anhydrous borates, which have no water incorporated into their structure, are found in metamorphic and igneous rock. Hydrous borates, minerals with water incorporated into their structure, form by the evaporation of mineral-rich water (evaporite minerals) on desert playas. Hydrous borates are relatively soft, white, colorless, or transparent minerals. Ulexite, colemanite, and borax are the most common borate minerals found in Death Valley. Borax is an ingredient in many laundry products. Photo from NPS archives. Uses for borax Boron compounds have many household and industrial uses. Boron is a common ingredient of soaps, cleansers, herbicides, soldering fluxes, gasoline antiknock compounds, pharmaceuticals, water softeners, food preservatives, and fire retardants. Boron is also added in the manufacture of glass, pyrex, and porcelain enamels used on kitchen appliances, sinks, bathtubs, stoves, and other products.

Borate Minerals in Death Valley After H. Majmundar,1985 Mineral Name Composition Sodium borates: Borax Na2B4O7 10H2O Sborgite Na2B5O8 5H2O Tincalconite Na2B4O7 5H2O Calcium borates: Colemanite Ca2B6O11 5H2O Ginorite Ca2B14O23 8H2O Gowerite Ca2B6O10 5H2O Inyoite Ca2B6O11 13H2O Meyerhofferite Ca2B6O11 7H2O Nobleite CaB6O11 4H2O Priceite Ca4B10O19 7H2O Magnesium Borates: Hungchaoite MgB4O7 9H2O Inderite Mg2B6O11 15H2O Kurnakovite Mg2B6O11 15H2O Macollisterite Mg2B12O20 15H2O Strontium borate: Tunellite SrB6O10 4H2O Sodium-calcium borates: proberite NaCaB5O9 5H2O Ulexite NaCaB5O9 8H2O Sodium-magnesium borate: Rivadavite Na6MgB24O40 22H2O Sodium-silicon borate: Searlesite NaBSi2O6 H2O Calcium-magnesium borates: Carboborite Ca2Mg(CO3)(B2O5) 1OH2O Hydroborocite CaMgB6O11 6H2O Wardsmithite Ca5MgB24O42 30H2O Calcium-silicon borates: Bakerite Ca8B10Si6O35 6H2O Howlite Ca2SiB5O9(OH)5 Calcium-strontium borate: Valkovite (Ca,Sr)2B14O23 8H2O Natural boric acid: Sassolite H3BO3

| Death Valley geology | Death Valley National Park | Geology field trip | | Death Valley time| Geologist's page | Image gallery | | USGS Geology in the Parks home | NPS Park Geology Tour home | This site is a cooperative endeavor of the US Geological Survey Western Earth Surface Processes Team and the National Park Service. Please share your comments and suggestions with us! parkgeology@den.nps.gov http://www.nature.nps.gov/grd/usgsnps/deva/fthar4.html This page was last updated on 6/20/00