IRVINE — Jerry Parton waded slowly down Station Camp Creek, scanning the rocky bottom beneath shallow riffles.
He carried a plastic bucket in one hand and a three-pronged rake in the other, using it to turn over stones now and then. Parton bent down, picked up one and rolled it in his hand. Then he shook his head.
"It's just a piece of hamburger," he said, referring to a round, ridged rock that looks like Kentucky agate but isn't. "I always have high hopes for those."
Parton, who lives in Mount Pleasant, Iowa, was part of a record crowd of 150 rock hounds from 13 states who came to Estill County last week for three guided hunts before the Kentucky Agate, Rock Gem & Jewelry Show.
The show is part of the Mountain Mushroom Festival, which began Friday and continues through Sunday. This is the 25th year Irvine has celebrated the tasty morel mushrooms that grow wild in the surrounding hills and the eighth year the festival also has showcased rare Kentucky agate.
Other events include a mushroom market and cooking demonstrations, car and craft shows, a beauty pageant, the Fungus 5k Run and the Speedy Spore River Run. Last year's festival brought 20,000 people to this town of 2,400.
"These are things that make us unique, and we want people to see what a nice community we have here," said Francine Bonny, the festival's chairwoman. "We're salt-of-the-earth people."
Kentucky agate is found only in Estill and parts of five adjacent counties: Madison, Lee, Rockcastle, Jackson and Powell. Spring is the best time to find it. Heavy rains tend to wash chunks out of underground bedrock formations into creek beds freshly cleared of algae.
The General Assembly declared agate the state rock in 2000, even though it is mineral quartz and technically not a rock. (Legislators struggle with science. They also declared coal the state mineral, even though it is a rock and not a mineral.)
Geologists think Kentucky agate was formed as part of the Borden layer during the Mississippian period, about 350 million years ago.
Agate stones appear rather ordinary on the outside. When broken open, they look like translucent glass with irregular, concentric bands combining red, orange, yellow, black and gray. The coloration is caused by various chemical impurities.
Collectors often use rock saws to cut agate into slices. They then polish them for display or use in decorative items such as jewelry or bookends.
Rondle Lee was giving away pieces of unpolished agate last Tuesday morning to people who signed up for one of the festival's three official hunts. Lee wanted everyone to know what they were looking for, because locals say the stretch of creek on his property contains some of the finest agate in Kentucky.
James Flynn of Irvine, who has been hunting agate for 35 years, led the group on a one-mile hike to the creek, followed by a long wade upstream.
Bright sunshine made it a good day for hunting, Flynn said, because the agate's coloring would stand out better from limestone and sandstone. Hunters tried to be choosey: whatever they put in their bucket or backpack had to be worth carrying around all day.
"Until about the 1960s, nobody knew this agate was here," Flynn said. "A lot of people come and hunt now. I've gone many a day and not found a piece. Other days, I've found a pack full."
Dan Newbauer of Apple Valley, Minn., came to hunt last April and enjoyed it so much he returned this year. Others, such as Esta Helms of Columbia, Mo., and Richard and Linda Schlabach of Nashville came after hearing about it from other members of their rock hound clubs.
"It's just a totally different kind of agate," said hunter Chip Burnett, a retiree from Killeen, Texas, who collects rocks, makes jewelry and has sold his wares at the Irvine show for four years.
"If you want some of this stuff, this is where you have to come," he said. "But it's beautiful country with a lot of friendly people."