Cornerstone Industrial Minerals

04/19/2017

CORNERSTONE IS HIRING!!
We are taking applications for a position as Laborer. Please pick up an application at the office Monday through Friday, 7am - 5pm. Prospective employees are required to pass a drug test and have a valid driver's license.

04/17/2017

RECLAMATION:

The company seeks to meet or surpass all environmental regulations and guidelines.

Cornerstone whenever possible, conducts land reclamation concurrently with the mining operations. Reclamation consists of contouring the land and seeding to reestablish the flora. The first photo below shows how a test pit on the property was reclaimed and seeded.

The topsoil form the current quarry is stockpiled along the edge of the operation in order to be used to reestablish vegetation when the operations have ceased. The stockpiles are seeded in their interim location in order to stabilize the soil and prevent noxious w**d growth.

04/17/2017

LOCAL GEOLOGY:

The Tucker Hill rhyolite dome complex is a package of cooling units related to several rhyolitic vents that originated from a single volcanic event. As a result of differential cooling, Tucker Hill demonstrates distinct lateral and vertical zonation (see geologic cross section). Two major cooling units are recognized, an outer chill margin and an inner rhyolitic core. Vesicle (air pocket) abundance within the rock increases outwards from the rhyolite core through the chill margin as a result of degassing and quenching of the once molten lava.

The chill margin was originally obsidian that was converted to perlite as the result of secondary hydration through continued contact with meteoric waters. The obsidian that remains is found as local zones of "apache tiers".

The chill margin contains various sub-units of perlite ore. The perlite sub-units are based on textural differences that resulted from variable degassing. The textures have been extensively mapped at the Tucker Hill pit in order to maintain a high quality product.

Differential erosion of the Tucker Hill lava dome has removed portions of the outer glass envelope, exposing the rhyolite core. (see geologic cross section)

04/17/2017

HISTORY:

Interest in the Tucker Hill area goes back to 1949 when a group of local prospectors staked claims on outcropping perlite located in the northwestern portion of the present property block. A bulk sample expansion test was favorable, and small-scale mining was conducted until 1954. Mining was concentrated on an area that was easily accessible but contained a high percentage of obsidian nodules. Adjacent areas of high-purity perlite went unrecognized.

In the early 1980's, geologists conducting reconnaissance in the area identified high-quality perlite south of the old mine. After continued evaluation through core drilling and bulk sampling the presence of a significant resource of commercial grade perlite was confirmed. The evaluation of the property continued though to the mid 1990's at which time a decision was made to move forward with development. Cornerstone a public company was formed and construction of the processing plant began in 1996, with production commencing in February of 1997.

Seven Peaks Mining Co. purchased the operation in early 1999. After acquiring the operation, Seven Peaks Mining Inc. embarked on a $1.5 million dollar program to renovate and expand the processing plant.

04/17/2017

Perlite is a naturally occurring volcanic glass that contains between 2 and 5 percent water in the glass structure. When subjected to heat, the Perlite will expand up to 20 times its original volume. The expansion is due to a change in state of the water found within the structure of the rock. The physical properties of the light weight expanded perlite give this product unique commercial value for building construction, horticulture, and industrial uses.
The expanded perlite is ideal for use in lightweight acoustical and thermal insulating plaster materials, insulating and lightweight concrete, horticultural, and as a filtering medium. Cornerstone's perlite is dominantly used in building construction products and horticultural applications.

04/17/2017

Mining is conducted at the Tucker Hill pit, 35 miles north of Lakeview, Oregon. Topsoil and organic matter are stripped from the surface and stockpiled for post mining reclamation. The ore is then drilled and blasted. All blast areas are mapped and drill holes sampled for expandability tests. In order to assure product quality, ore mining dig plans are designed on information gathered from this geological mapping and associated sample tests.

The ore is crushed to minus 1 ½" at the quarry site and stockpiled. The crushed perlite ore is loaded by Cornerstone personnel into over-the-road trucks operated by a local contractor and delivered to the processing facility.

The crushed perlite is reduced in size and sent through a rotary kiln drier. The ore is then further reduced using a VSI crusher and then processed through four new state-of-the-art separating screens. The various grades of processed perlite are stored in silos with a total capacity of 1,300 tons. The perlite ore is then blended to meet the customer's specifications and loaded onto trucks or rail cars.

Processed perlite can be delivered from the Lakeview processing facility via rail or truck.

A quality control laboratory equipped with a test furnace is utilized to assure finished product meets or exceeds the requirements of customers. Additional samples are sent to outside labs to insure continued quality.

04/17/2017

Cornerstone Industrial Minerals Corporation is a privately held industrial minerals company engaged in the mining, processing, and marketing of perlite. The primary asset of the company is the Tucker Hill operation located in south central Oregon.

The company's assets in Lake County, Oregon consist of the mine which contains the Tucker Hill perlite deposit, and the processing facility in Lakeview.

The mine property consists of 800 acres of unpatented mining claims located on land administered by the Bureau of Land Management (BLM). Drilling and sampling have delineated a measured perlite reserve of 4.9 million tons and a property inferred resource in excess of 30 million tons. Test work on core and bulk samples indicate that Tucker Hill perlite exceeds industry standards for expanded density, furnace yield, and compacted density.

The processing facility is located on an industrial park in Lakeview; it is served by good highway and rail connections. Lakeview and the mill are located on a rail spur operated by a short line carrier that is linked to the Union Pacific Railroad (UP) System

04/17/2017