Rome

Rome, Oregon

St. Cloud’s Rome mordenite (a zeolite mineral) deposit is located approximately 6 miles west of Rome, Oregon, in Malheur County. Rome is the largest deposit of drilled out high-purity mordenite in the United States, and has potential for use as animal litter and in cementitious and pozzolanic applications. St. Cloud is currently assessing the potential of the reserve, and controls the deposit through unpatented placer mining claims. Local facilities are used to toll process material from the deposit for application testing, and there is a pit and small stockpile of mine run product available for sampling.

Geology, Exploration Drilling and Analytical Test Work

The Rome deposit contains a lower and upper mordenite horizon, separated by an internal waste horizon. Based on exploration drilling, the lower horizon is up to 10.8 feet thick and the upper horizon is up to 16.0 feet thick, and they are separated by an internal waste zeolite horizon averaging 3.6 feet.

Based on XRD of the drill hole samples, both the lower and upper mordenite horizons contain 60% mordenite and there are other zeolite and non-zeolite minerals present. Other zeolite minerals include clinoptilolite and phillipsite. Non-zeolite minerals include quartz, feldspar, calcite, fluorite, and volcanic glass.

In the 1970s and 1980s, Anaconda Minerals Company determined bulk densities for Rome’s lower and upper mordenite horizons, which ranged from 24.6 to 25.9 pounds per cubic foot for granular 6 x 30 mesh product. Additionally, the water absorption percentage ranged from 108 to 120.

Product

Mordenite

Designation

OR-UB

Primary Exchange Cations

Calcium, Sodium, Magnesium, Potassium

Designation

OR-LB

Primary Exchange Cations

Calcium, Sodium, Magnesium, Potassium

About This Location

  • Largest and highest grade mordenite deposit in North America
  • Potential of this reserve is currently being assessed
  • Based on drilling from 1978 to 1980, the estimated reserve for the lower and upper horizons combined is approximately 2 million tons
  • Information from drilling conducted after 1980 will be utilized in updating the tonnage, grade (% mordenite), and classification as proven and probable reserves

Primary Applications