Macdonaldite [SEP] named after
Macdonaldite
Macdonaldite is a rare barium silicate mineral with a chemical formula of BaCaSiO(OH)·10HO. Macdonaldite was first described in 1965 and named for Gordon A. MacDonald (1911–1978) an American volcanologist at the University of Hawaii. 
Macdonaldite crystallises in the orthorhombic system. Macdonaldite is anisotropic with low relief. 
Macdonaldite appears as veins and fracture coatings in a sanbornite and quartz bearing metamorphic rock. Macdonaldite was first described in 1965 for an occurrence near the Big Creek-Rush Creek area in Fresno County, California. It has also been reported
Fresno County is part of the Madera AVA wine region.
Fresno was actually named after two particular ash trees that grew near the town of Minkler on the Kings River, one of which is still alive and standing.
Geography National protected areas.
- Giant Sequoia National Monument (part)
- Kings Canyon National Park (part)
- Sequoia National Forest (part)
- Sierra National Forest (part)
Geography Geology.
A number of minerals have been discovered in the county, including macdonaldite,