Hazen Corundum prospect (Unnamed Corundum prospect), Soboba Hot Springs (Ritchey Hot Springs; White Sulphur Spring), San Jacinto Mountains, Riverside County, California, USAi

Regional Level Types
Hazen Corundum prospect (Unnamed Corundum prospect)	Prospect
Soboba Hot Springs (Ritchey Hot Springs; White Sulphur Spring)	Hot Springs
San Jacinto Mountains	Mountain Range
Riverside County	County
California	State
USA	Country

A corundum occurrence located in sec. 5, T4S, R1E, SBM, on the northwestern flank of the San Jacinto Mountains, 6.2 km (3.9 miles) NNE of Soboba Hot Springs, about 2 miles from the Potrero shaft of the Metropolitan Water District Aqueduct system. MRDS database stated accuracy for this locality is 1,000 meters.

Local rocks include Mesozoic granitic rocks , unit 2 (Peninsular Ranges).

In 1939, large crystals of corundum embedded in mica schist were submitted to the Department of Geology at UCLA, by Mr. B. G. Funk of Los Angeles. These specimens showed sapphire-blue cores, with a progressively zoned gray colored outer rim included with micaceous material. The locality was visited around 1940 by Joseph Murdoch and Robert Wallace Webb, with permission of owner Guy E. Hazen, of Wickiup, Arizona, in the hope of finding sapphire of commercial quality.

According to Murdoch and Webb, the deposit is a series of metamorphosed sedimentary rocks consisting of mica schists, quartzites, and marbles, primarily within a large roof pendant and smaller xenolithic masses. These rock types are considered remnants of an extensive morphological sequence of probable Paleozoic age. The rocks have been extensively intruded by diorites and gabbros, followed by granite and quartz monzonite. The quartz monzonite is only found in the corundum area. Subsequent erosion resulted in deeply weathered soil slopes in the plutonic rocks, leaving hillocks supported by metamorphic remnants. The corundum in this occurrence is thought to have formed during the metamorphism of a highly aluminous sedimentary rock, under dynamic hydrothermal conditions. No evidence was found suggesting the introduction of aluminous material during invasion of batholitic rocks younger than the metasedimentary sequences.

Adjacent to the corundum deposit, several areas of garnet-diopside-wollastonite-quartz mineralization occur along the contact zone of marbles that extend into the roof pendant for a distance of up to 300 feet. These tactite formations are characterized as massive and crystallized grossularite in a matrix of white quartz, with calcite and large radiating clusters of white wollastonite, and minor amounts of diopside.

The corundum crystals recovered were described as barrel-shaped forms, varying in sample size from microscopic to large crystals 14 inches in length and two inches in diameter, coated with muscovite and biotite. These crystals occur both parallel and transverse to the foliation of the biotite schist host rock, which in places can be described as nearly biotite gneiss. The corundum is occasionally blue enough so that the color is visible to the naked eye, but out of several hundred specimens examined, none were found to be considered suitable for lapidary purposes.

These corundum-bearing rocks occur over a wide distribution within the general area, as suggested by the many fragments of crystals found along weathered slopes within a mile of the main exposure. Similar corundum crystals are said to have been found as float in many other parts of the San Jacinto Mountains.

Other Databases

Link to USGS MRDS:	10189058

Other Regions, Features and Areas containing this locality

References