The Vallejo Gem and Mineral Society’s building has become a must-see for some visitors to the Solano County Fair.

From a display case of jewelry that can be won in the club’s drawings to the giant wheel that lets children spin for other prizes, the club has opportunities for fairgoers to take home a souvenir.

Arranged on the club’s counters are more pieces of jewelry that members have made for sale.

And to one side, the club has displays of crystals and semi-precious stones of all types — such as orange citrine, petrified wood, colorful agates, streaked rainbow obsidian, bright purple amethyst points, large lumps of turquoise and a variety of fossils.

In one display box are two rows of dowel sticks, and on each is a carefully worked oval of stone — cabochons that have been cut by club members.

Making those cabochons is the first assignment new members are given, said Robert Regalado, one of the newer members of the club. He and his wife, Lucia, just joined three months ago.

But he already has joined the club on a few field trips. “And I had good success,” he said.

He’s learning to tell the worthy stones from the “leaverites.” Like many new members, he had to ask what a “leaverite” is.

“You leave ’er right where it is,” he was told.

Once a member successfully cuts three cabochons, he or she then can be trusted to use the machinery that is powerful enough to slice through stone. Until then, the member must be supervised.

For his project, Regalado chose aventurine, a green quartz that has inclusions that makes the stone glisten. Larger pieces of aventurine have been used in landscaping and building or in monuments. But it also is popular for jewelry.

“I like the color,” Regalado said as he held two of the three cabochons he has made. He hasn’t decided yet what he’ll do with the three pieces — perhaps make jewelry for himself and his wife.

The Vallejo Gem and Mineral Society, which meets in its building at the Solano County Fairgrounds, was formed by lapidary enthusiasts, often called “rock hounds,” in 1954. Members share not only rock-shaping methods but also such jewelry-making technique as lost wax and wire wrapping, beading and silversmithing.

Its website is http://vjgems.com.

Regalado and other club members have been greeting fairgoers all week, and the building, near the livestock barn, is open Sunday, the final day of the fair.

In addition to the Gem and Mineral Society, fairgoers can see Jeripeo con Toros Bravos, Banda Ahuatian, Kajukenbo self-defense, Grateful Sirens Belly Dancers, CC Amato and the Rob Tracy Band and UB707.

Yo-yo champion Daniel Kim will show off his skills with the toy that once was used as a weapon.

Also performing Sunday are Vai Hau Nui Polynesian dancers, San Francisco Scottish Fiddlers, hypnotist Steve Bayner, LJ Matias and Christian Bayutas, Alexis Scott, Alexis Doria, the Ascension Band and Larz De’Lago.

In the Family Fun Zone, children can participate in crafts. Also available there are the Puppets and Players Little Theatre, the Americana Roadshow, Sadie’s Farm-tastic Adventure Show, Sacred Fire dancers and the First 5 Solano giant sandbox.

Fairgoers also can watch the youth and adult cooking contests and attend a “horse racing 101” beginners’ seminar, or can try to win prizes and challenge thrilling rides on the midway.

The final concert starts at 6 p.m. Sunday on the Galaxy Stage and stars Los Canarios de Michoacan, with Banda La Grande de Jalisco and Los Tremendos de Mexico.

The fair’s website is www.scfair.com.

Admission is $10 for adult general admission, $6 for children 6 to 12, those 60 and older and military veterans. Those 5 and younger and active duty military with identification are admitted at no charge.

Carnival wristbands, allowing the purchaser to ride all day are $25. Parking is $10.