DESIGN : Glasswork Quality Is Crystal Clear Only to the Most Practiced Plink : The difference between a superior hand-cut piece and an inexpensive, machine-made one is deceptive. Prices, however, seldom are.

Beau Mooney holds two crystal champagne flutes in his hands, turning them so they sparkle and fire under the light.

One glass sells for $50, the other for $9.95.

“Can you see the difference?” Mooney asks. “Appearances can be deceiving.”

To reveal which is the fine crystal, he flicks his finger against each thin glass. One sounds a clear note, indicating the presence of lead oxide. The other flute emits a muffled thud.

“You can tell by the tone, and the prices always tell you,” says Mooney, owner of Laguna Crystal in Laguna Beach.

As Mooney demonstrates, the difference between a superior hand-cut piece of crystal and an inexpensive, machine-made one isn’t always clear.

Without a name such as Waterford or Baccarat etched into the glass, many couldn’t distinguish a fine crystal flute from an inexpensive copy. So why pay more for the flute with the fancy name?

“Why does someone spend thousands for a Renoir?” Mooney asks with a shrug.

Superior artistry and a limited supply enhance the value of crystal and glassworks, sending the price of a single vase or sculpture into the thousands.

Tiffany & Co. in Costa Mesa’s South Coast Plaza recently unveiled its exclusive collection of colored glassworks by Archimede Seguso, a Venetian glassmaker of renowned skill whose family has blown glass for 500 years.

Seguso, 81, still spends each day blowing glass at his factory in Murano. He will be the last in his line to do so--his sons did not take up glassmaking.

When Seguso stops working, he will take with him the secrets of his trade: How he makes opaque clouds billow up inside a bowl of translucent green, how he creates the filigrains, feathers and lace patterns in the glass, and how he achieves his unique forms and colors.

Like fine paintings, each of the hand-blown pieces is signed and numbered by its creator. Seguso has created 14 limited-edition designs for the Tiffany collection. Eventually he will complete just seven copies of each design, keeping two for himself and selling the other five through Tiffany for $5,300 to $9,000 apiece.

“It’s the only time Seguso has done a collection of this magnitude,” says Jo Ellen Qualls, vice president of Tiffany & Co. in South Coast Plaza.

At Galleri Orrefors & Kosta Boda in South Coast Plaza’s Crystal Court, an exhibit of icy sculptures by 12 designers from Sweden shows how different artists reveal their personalities through crystal.

“All of us differ in our views on the glass. It has so many ways of expressing itself,” says Goran Warff, a Swedish designer addressing a recent benefit at the store.

“It’s a very personal and intimate medium to work with,” he says.

Warff creates free-form sculptures--a flattened oval saucer of the purest crystal, a triangular-shaped vase with just a single strip of cobalt blue for color, and an orb-like sculpture with two bubbles and a blue ring suspended in space.

“His designs are so simple. The line is what it needs to be and no more,” says John Smart, spokesman for Orrefors and Kosta Boda. “There are no crosscuts or anything.”

Each of the designers has a distinctive style. One wraps crystal cobras around opaque vases, another forms the crystal into geometric shapes adorned with spirals, polka dots and solid bands of colors.

“I tell people, ‘Don’t even think of it as a bowl or a vase. Think of it as art,” Smart says.

A background in industrial design has helped Thomas Bastide become the leading designer for Baccarat, a French company known for fine contemporary crystal.

“For me, modern means simple,” says Bastide, who flew from his home and studio in Paris to sign his work at Bullock’s in South Coast Plaza.

At 35, Bastide has been Baccarat’s most prolific contributor since 1982. He turns out 100 designs a year for the company, a full 80% of the collection.

His love of mechanics can be seen in his “Milan Bowl,” a centerpiece shaped like a section of wheel with a gear at the base, or in the grid carved onto the flat face of his “Neptune” vase No. 1.

Even the tigers, bears and sharks he conjures out of crystal remind one more of powerful machines than creatures of nature.

“He doesn’t do cute animals,” says Sylvie Jouan, spokeswoman for Baccarat. “He shows their strength.”

Bastide first became fascinated with glass as a child, when he met a neighbor who made windows using pieces of colored glass.

Inspired by the vision of the shiny glass, he eventually learned to transfer his knowledge of industrial design to the medium of crystal. He begins by making a sketch of his creation, then forming a small model out of clay and finally a full-size piece in plaster. His work is then executed in crystal by artisans at the Baccarat factory.

Bastide prefers designs that combine elements from the “hot work,” the soft bubble shapes formed when the crystal is blown, and the “cold work,” the grooves and planes revealed in the cutting. Thus, when looking at a piece such as the Neptune vase, one often can peer through the flat planes at softer shapes within.

“I like to use all of the possibilities,” he says. “When you turn the glass it should be magic.”

Choosing fine crystal is more a matter of taste than an exact science.

“A fabulous piece will have very clear brilliance and clarity. It will catch and scatter the light,” Mooney says “It will have more sparkle and shine to it--a character given to it by the presence of lead oxide.”

Crystal is formed by melting a mixture of fine sand called silica with lead oxide, a potassium compound made from wood ash, called potash, and chemicals. A mixture can have no lead oxide and still be classified crystal, but to be considered a full lead crystal it must have at least 24% lead oxide.

A greater lead oxide content in the crystal will create a clear luster, says Ed Kaplan, co-owner of the Crystal Inn in Laguna Beach.

“It makes the glass much harder, and more durable. They can cut deeper into the crystal,” he says.

“When you see something advertised as having 24% lead, that’s the minimum.” Finer crystals such as Baccarat, Waterford and Lalique use 30% to 33% lead oxide, Kaplan says.

Most crystal collectors favor hand-cut pieces over crystal that’s been pressed from a mold, although Mooney says the machine-made variety has become so sophisticated that the two are virtually indistinguishable.

“There is a misconception that hand-cut pieces have sharper edges,” he says.

In fact, hand-cut crystal loses its sharp edges during a process called “annealing.” Once the crystal is cut, it’s returned to the kiln to be re-heated almost to the melting point. This strengthens the piece and smoothes the edges.

“If not for annealing, the crystal would chip easily and the cuts would be very sharp,” Mooney says. Smooth edges therefore do not mean a piece is machine-made.

“The name (of the crystal maker) is the only way to be sure it’s hand-cut.”

By looking closely at a hand-cut piece, however, one can usually discern slight differences in the depths and widths of the cuts. Far from being flaws, the discrepancies give the work its handmade character.

Some companies are known for the quality of their cutting. Kaplan lists Baccarat, Lalique, St. Louis, Daum and Orrefors as among the top crystal makers today.

“A lot of people ask which is best crystal. The best is what you like,” Kaplan says.

“If you like modern, simple lines, you’ll like Orrefors or Baccarat. If you like a more heavily cut crystal, you’ll like St. Louis.”

Like fashion, certain styles of crystal fall in and out of favor.

“A few years ago busy patterns were popular. People wanted heavily cut crystal. Now the trend is to more modern, less busy crystal,” Mooney says. He finds the free-form designs characteristic of Orrefors to be in style now.

“It’s entirely subjective,” he says. “Any good artwork is a matter of taste.”