The Old Dutch Cleanser Mine

The Old Dutch Cleanser Mine

By Dr. Ralph E. Pray
The naturally-occurring white scouring powder called Old Dutch Cleanser, originally from Kern County, California, is a house-hold helper known throughout the U.S. As a sink, stove, and tub cleaner, the abrasive pumicite is one of the most popular scrubbing agents on the market. Bon Ami and Comet are names of similar products.
The original source of this Old Dutch Cleanser material, a pumicite mine hidden underground in the remote Mojave desert, produced 120,000 tons of cleansing powder. The mine, along the Garlock Fault, closed in 1947. There remains in the property an incalculable tonnage of pumicite identical to that marketed so long ago, a portion of which has recently been mined economically from the surface. Pumicite recovered from many areas of former volcanic activity is now used chiefly as an additive to Portland cement, paint and as a hard, white, flint-like filler. Here in my laboratory a prepared 20-mesh sample of pumicite from the old mine was added to deck paint and applied on porch steps. This provided a non-skid surface, both wet and dry, for years.


The mine, 130 miles north of Los Angeles, is located on 240 acres of patented land in Township 29 South, Range 38 East, Mount Diablo Meridian, Kern County, California. The property is in the El Paso Mountains which are 30 miles north of the city of Mojave on State Highway 14, then easterly 4.3 miles.
The boundary of Red Rock Canyon State Park, a popular tourist attraction since the early 1970's, surrounds the mine property. The Last Chance Canyon dirt road lies far below the pumicite outcropping.
Elevations above sea level near the mine workings shift dramatically between 2,800 feet and 3,500 feet along the northeast-southwest trending spine of the 1.5 mile-long land parcel. On a windy day the 700-foot drop-off makes hiking near the edge a risky business.
The area is typical of the Mojave Desert. It receives less than five inches of rainfall annually in clear, dry air. Summer daytime temperatures generally exceed 100 degrees; winters are mild to cold, with night-time temperatures falling below freezing.
Highway 14, a major east-west route between freeways leading north out of Los Angeles and U.S. Highway 395 going north to Bishop, California and Reno, Nevada, passes within a few miles of the property.


Pumicite production from the property began in 1923 under the auspices of the Cudahy Packing Company. Material was removed from underground workings along wide drifts on a vein height up to 21 feet from floor to ceiling. The large side-by-side portals of these workings on the face of the white outcrop are still completely intact.
During the early mining period hand labor was used to remove slabs of the semi-hard, brittle material for placement in 1-1/2-ton side-dumping cars pulled up out of the mine into daylight by burros. Twelve men were employed to produce 100 tons of pumicite per week. While remote western ores were hauled to shipping centers by burro or mule-team, the ore from The Old Dutch Cleanser mine was lowered to loading bins over a 475-foot- long inclined rail tramway. Evidence of this unusual conveyance is easily observed today, most safely from the lower roads.
From the base of the rail tramway the mined rock was trucked to a siding on the Southern Pacific Railroad seven miles due south of the mine. The tramway on the western workings was shut down when a road was built to the eastern workings on the same vein. Truck loading was then employed near the working portals. Rail cars delivered the ore to Los Angeles, where it was ground and blended with other material to produce a disinfecting scouring powder. The product was and is widely known throughout the U.S. as Old Dutch Cleanser, a domestic kitchen and bathroom scouring agent. Beginning in 1947 the manufacturers obtained their pumicite from other sources.


The mineral deposit containing pumicite is in the El Paso Mountains. It is contained within the sedimentary layers in the lower half of the 7,000 foot-thick Ricardo formation of Pliocene age. The deposit crops out as part of a nearly continuous northeast-trending belt that measures up to 600 feet in thickness. It stretches 7 miles northeast from the general vicinity of the old site of Red Rock, at the mouth of Redrock Canyon, to the south slopes of Black Mountain. Sands, clays, and ash were deposited in a lake which, in geologic time, began to develop north of Ricardo. Much of this formation is easy to see from the public roads winding through Last Chance Canyon.
The Old Dutch Cleanser deposit is the thickest and uppermost of six layers of white, thin-bedded, fine-grained, pumicite. The pumicite is interstratified with various other pale-colored sedimentary rocks which comprise member 4 of the Pliocene Ricardo formation; its dip is 15-20 degrees NW. The uppermost layer is 21 feet thick at the easterly mine site and for several hundred feet southwest. Elsewhere it is less than 21 feet thick and the whole of member 4, which is a maximum of 600 feet thick southwest of the mine, pinches out about 1-1/2 miles northeast of the mine. The 21-foot layer of pumicite crops out a few tens offset below the sharp southeast crest of a northeast-trending ridge. The other five layers of pumicite can be seen as outcrops lower on the southeast slope of the ridge.


The natural resource assets on the mineral property fall into two highly specific categories, (1) pumicite, frequently classified in the mineral industry as an abrasive and a filler, and (2) bentonite, a swelling clay substance generally identified as either a calcium-bentonite or a sodium- bentonite.
The pumicite is in the form of loosely consolidated glass-like needles and crystal-like particles of volcanic ash made up chiefly of silica. The form results from particles settling out of the atmosphere, following explosive volcanic eruption, onto either dry land or through a water body. The mineral occurs as a fine powder in the compressed irregular bedded deposit, and differs from pumice in its much finer particle size and friability.


The mineral pumicite in the Ricardo formation lies exposed along its upward thrust edge facing southerly for a distance of over 7,000 feet on the patented property. The original mine openings, spanning a distance along strike of 1,800 feet, were extended down-dip for several hundred feet on the pumicite layer. The pumicite layer thickness in the underground workings is 21 feet at the easterly end of the outcrop. The layer thickness at the other end, 1800 feet westerly, is 9 feet. An impressive tonnage of pure white pumicite lies near the surface and is sporadically mined in truckload quantities. Also, there may be as many as one million tons of pumicite available down dip along the exposed 7,000 foot strike. Coal seams lying in a similar horizontal attitude are mined using continuous mechanical miners. At this time pumicite mined by large surface excavation elsewhere in the U.S. controls the market price of the commodity.
Published in Prospecting and Mining Journal, 2003.
Reprinted with permission of the author.
Dr. Ralph Pray, Mining & Metallurgy
805 S Shamrock Ave
Monrovia, CA 91016
Telephone: 626-357-6511
Fax: 626-358-8386