Rediscovering Arizona onyx
In 1987, Ray Bosiljcic founded a masonry company in the Phoenix, AZ, area. Over time, the operation known as Stoneworld International expanded to include a stone yard, and he eventually began seeking quarry sites for flagstone and sandstone. The company now has two full-scale fabricating facilities in Ash Fork, AZ, and 18 quarry sites in Arizona for sandstone, flagstone and cantera as well as a quarry in New Mexico for travertine. But even with this steady pattern of growth, the company's boldest move may have come most recently, with the re-opening of an historic onyx quarry in Mayer, AZ.
Stoneworld International began working to reopen the quarry three years ago. The site lies along Big Bug Creek in Mayer, an old cowboy town about 75 miles from Phoenix that is 5,000 feet above sea level. One of the first speculators on the site was a man by the name of William â€œBuckyâ€ O'Neill, a lawyer, miner, cowboy, sheriff and congressman who was one of Teddy Roosevelt's â€œRough Ridersâ€ during the Spanish-American War. O'Neill paid $150 for his one-third share of the mine, and shortly thereafter discovered that the site had â€œthe richest deposit of onyx between Prescott, AZ, and Puebla, Mexico,â€ according to historical documents.
In March of 1893, O'Neill and his partners sold their interests in the regal sum of $200,000, and an investment of â€œover $10,000 worth of fine machineryâ€ was purchased by George C. Underhill, a well-known specialist and examiner of stones from Rutland, VT. Underhill's new venture was named the Arizona Onyx Co. Experts in Chicago and San Francisco attested to the value of the quarry's yield, and the stone was exhibited and sold around the country as a premium material. Even the Ford Motor Co. began using the onyx as interior ornamentation for its new automobiles. However, as was the case with many quarries in the U.S., the site eventually closed during the Great Depression, and it laid dormant for over 70 years.
Stoneworld International has reawakened the ghosts of Bucky O'Neill with this venture, and a drive from its offices in Scottsdale, AZ, to Mayer takes visitors through areas like Horsethief Basin, Deadman Basin and Bloody Basin -- places where Billy the Kid is part of the local vernacular.
The stone -- referred to the company as â€œGrand Canyon onyxâ€ -- comes in two predominant varieties. The first is â€œBlack and White,â€ which is a combination of dark brown, black, gray, beige, caramel and cream swirls. The second is â€œGrand Canyon Red,â€ which is predominantly a dark reddish/orange mix with beiges and browns and small circular swirls of black, cream and light orange.
Despite the rural feel to the town of Mayer, the onyx quarry is actually quite easy access, as it sits only a few yards off Interstate 17. The parcel of land containing the quarry is 260 acres in all, and stone has been pulled from various locations across an area of 40 acres. The quarry has very little overburden, and areas adjacent to the quarry appear to be rich in natural stone. A river runs through the site, and when it is running, it reveals boulders of onyx lying loosely in the riverbed.
Although the onyx quarried at the site is said to be harder than typical onyx varieties, no blasting is necessary. Stone is extracted by means of vertical drilling and cutting with a diamond wire saw, and water bags are filled to separate sections of stone from the quarry face. Currently, production stands at 500 tons of stone per month, according to Leo Nicovic of Stoneworld International.
After blocks are pulled, the stone can be cut and polished either vertically or horizontally. Nicovic explained that when cut in the same direction of the vein, the surface will show the coloration of one layer, and when cut across the vein, the surface will show multiple layers.
Stone is processed into finished products at the company's fabricating facilities in Ash Fork. For tile production, blocks are processed on a GMM Quadra block cutter from Italy. This unit automatically cuts blocks into strips as wide as 24 inches. The resulting strips then move on to the tile line, which includes a Simec LM 600 calibration/polishing unit for strips up to 24 inches in size and a Breton automatic filling line that is comprised of the following units (in order of processing): an electric oven, an automated dispenser, resin propellers, a second electrical oven and a UV oven. There is also a Donatoni automatic stone strip handling system, a Breton automated polishing unit for strips up to 32 inches wide, a Terzago crosscutter with seven heads, a Morendenti calibrating and chamfering machine and a Donatoni finishing line with fans, ovens, brushes and a selection table.
Blocks are cut into slabs with a Pellegrini DF 2500 stationary diamond wire saw, and cutting of architectural pieces is done with a Sawing Systems 411 C semiautomatic gantry saw, which can process material up to 16 inches in thickness. Supplemental polishing is completed as required with a Noma 2000 manual polishing machine.
The onyx is sold in tile sizes of 4 x 4, 12 x 12, 18 x 18 and 24 x 24 inches, and the company recommends that onyx tile be no thinner than 1â„2 inch (or 3â„4 inch for the 24- x 24-inch tiles). Stoneworld International also recommends that slabs are no thinner than 3â„4 inch and no longer than 5 feet for standard pieces.
Onyx finishes included polished, tumbled, antiqued (acid-treated) and saw cut. Since onyx is a premium material, the company is looking to transform it for applications beyond basic tiles and slabs. Architectural features can include doors, tables or feature walls, and Nicovic said the company is also working to produce laminated translucent onyx. These pieces will use thinner onyx with reduced weight, backed by glass or Kevlar, and they can be used for facades or backlit walls.