Pumice Deposits of the Klamath Indian Reservation, Klamath County, Oregon
Pumice Production in Oregon
In the past few years pumice production in the State of Oregon has been dominated by the various pumice producers in the Bend-Chemult area north of the Reservation. Most of the pumice has been sold to Oregon consumers, although small quantities have been sold outside the State, particularly to Washington and California producers of pumice blocks and acoustic plaster.
The total production of the State in 1948 was 170, 500 cubic yards’ valued at about $305, 000. This was an increase of about 40, 000 cubic yards over 1947 production. This material was used almost exclusively in making lightweight blocks and for acoustic plaster, though a very small quantity was shipped to eastern consumers for use as a low-grade abrasive. In 1949 production of pumice fell slightly to 169, 036 yards, owing in part to the increased use of haydite (thermally expanded clay or siltstone) and other expanded materials for lightweight aggregate. These synthetic lightweight materials usually have advantages over natural pumice, because their properties can be regulated to meet exacting specifications of grain size and porosity. Total production figures on pumice in Oregon for 1950 are not yet available but various pumice producers have reported that haydite production has again increased.