Attracting patrons predominantly from the Northeast, the Mohegan Sun Casino, located on the Mohegan Indian Reservation in Uncasville, CT, incorporates mythological tradition of the Mohegan tribe in its interior. Three years after the opening of the original casino in 1996, which is now referred to as the "Casino of the Earth," the Rockwell Group was hired as the interior architect for the public spaces of the 2.4 million-square-foot expansion. The final creation, completed in September 2001, included a large crystalline structure, Wombi Rock (meaning "white rock" in the Mohegan language), utilizing 22,000 square feet of polished onyx and honed Breccia Paradiso marble.

The New York City-based Rockwell Group defined a new way to approach this second phase of development, which is centered around the "Casino of the Sky." Based on the Mohegan concept of a "Life Trail," the interior architecture trans-forms from land and trees to water, rock and crystal, becoming the basis for the Casino of the Sky. Wombi Rock, 60 feet in diameter and 65 feet tall, stands underneath a 150-foot planetarium "sky" with interior lighting programmed to change colors along with the planetarium show. According to the design team, the ascent of this mountain represents a spiritual voyage, and at the summit one can almost touch the Celestial Bear, hovering amongst the stars.

Realizing an idea

Research on the Mohegan tribe conducted by the design team revealed that tribe members found crystals on the site where the casino was built. In addition, the tribe had a history of conducting important meetings on large rock formations in the area. This narrative history of the tribe led design plans to include a similar rock formation whose design was influenced by the crystals.

"Our concept was to anchor the center of the casino with a three-tier rock formation based on the crystals on site," said Ed Bakos, a Principal of the Rockwell Group. Attention to the transition of colors from the bottom of the structure to the top was the result of extensive research done on crystal structures. Stone shades were progressively lighter at the top of the structure, while the bottom featured darker shades of onyx.

According to Bakos, it was difficult to transform this complex idea into an actual application. Before settling on the use of onyx, architects looked into using colored glass, tile and alabaster. But in the end, a palette consisting of three shades of onyx - white, honey and green - was chosen. Additionally, the project featured 12,000 square feet of Breccia Paradiso marble, an opaque stone, to ensure that not all of the rock would be completely glowing. Both the onyx and Breccia Paradiso were quarried in the Middle East.

"The biggest problem was, 'How do you describe a complex faceted crystalline object?' " explained Bakos. "We couldn't describe the shape through traditional plans and elevations alone, and we wanted people to be able to walk inside and explore the peaks. We created a computer model that would describe the general crystalline form of the structure. The next problem was, "How to build it?" So, the construction manager - Perini Building Co.- brought in a subcontractor- the Raymond Co."

According to Kim Lorch of Raymond, the company's engineering department used three-dimensional programs to develop the structural frame in conjunction with 4,300 unique geometric translucent stone panels, which formed the finished structure. In addition, Raymond generated over 10,000 shop drawings to stone, steel, decking and glass fabricators to construct one of the world's largest jigsaw puzzles.

"We attribute our success on this project to a tenacious project management team working with a creative engineering department," said Lorch. "They took it one step at a time and delivered a quality project on time."

The onyx for the casino was fabricated and supplied by Santucci of Carrara, Italy. Santucci, which specializes in cut-to-size architectural work, custom-cut each of the onyx panels to fit the specifications by the design team.

Fastening the onyx

Several technical problems were encountered during the installation process, including the size of the panels that the onyx would be fastened to. "Limitations were the size of the natural product, the ability to lift them into place, how they would be faceted to a metal frame and structural issues involving stone pinned to a steel frame at odd angles and how to template all of the stone," said the architect. "The Raymond Co. took the computer model and started breaking down the facets into smaller sizes that would represent stone panels. We would then work with them and assign colors and stone species, so that we could control the color and achieve the color transition of the dark species at the ground and the white towards the sky."

According to Bakos, some stone pieces were inclined surfaces, some leaning out and some overhead. The original concept called for using 3/4-inch onyx panels, but the method for fastening the panels to the metal substructure was a cause for concern among the design team.

"Eventually, after a lot of deliberation, it was decided that we would use a very interesting product that would allow us to laminate the stone to glass to achieve a structural, engineered product," said Bakos. "Something that we would know the stresses and strains of so that we would be fairly certain that one of the panels wasn't going to fall off."

Once this new plan was agreed upon, the direction of the project shifted. According to Bakos, there was only one company in the world who they believed could accommodate this design. The stone fabricator, Santucci Graniti Srl, brought in Taltos S.p.A. to do the lamination. When meeting with Santucci, after the color range of the 3/4-inch stone was agreed upon, it was discovered that the onyx was a different color when cut to 6-mm-thick slices for lamination to the glass.

"We had to readjust the range of stone," said Bakos. "In order to achieve the structural qualities to proceed with the project, it ended up completely changing the color range. We shifted to some darker toned products."

The onyx slabs were laminated with safety glass and produced into 8- x 4-foot panels, which were cut to size by Santucci, explained David Brenman, president of Taltos. "We specialize in this," he said. "We literally treat stone by injecting epoxy resin [into it] and clad the back with galvanized steel mesh." Brenman also explaind that when glass is put on stone, it never changes color.

Overcoming challenges

A challenge from a logistical standpoint occurred just after the color range and size issues were resolved. According to Bakos, Raymond had already produced a computer model and issued drawings to the metal fabricator in Rhode Island for steel frames to be manufactured. Mean-while, the stone panels were being fabricated in Italy and were going to be shipped to Connecticut for application to the steel frames on site. There was no template. Fabricators instead relied solely on the computer model.

"We couldn't have done this without computer generation," said the architect.

Faced with yet another obstacle, Taltos' factory, north of Torino, Italy, was destroyed by a flood in December 2001. As a result, production of the laminated stone product was hindered. "It was really an amazing story of collaboration between Perini, the Raymond Co. and Taltos," said Bakos. "They worked out a schedule to get the factory back up and running and to begin delivering the laminated stone product on site. Right before [the casino] opened, the last piece of stone was going up on the structure."

But, despite the challenges, Casino of the Sky opened as scheduled. Located on the lowest level of the Wombi Rock are cash cages for coin redemption, while the second and third levels house a bar and dance floor. The third level overlooks the dance floor below as well as the casino.

"The Wombi Rock turned out spectacularly. When people walk through, they are just in awe of the structure. The beauty of the natural stone and the coloration of the onyx is incredible," said Bakos.