Even after 30 years, the thrill of finding a new agate never gets old for Roland McIntosh.
McIntosh is a expert on Kentucky agate — stones clustered largely in the Kentucky counties of Jackson, Powell and Estill. Uncut and unpolished, they look like seeing the earth from a low-flying airliner: intricate patterns of green and gray with an occasional pop of color.
These Kentucky agates have "a wider range of colors and patterns than any agate from anywhere in the world," McIntosh, 69, said. "Any time I open an agate it's a new adventure."
McIntosh and Warren Anderson, a research scientist at the Kentucky Geological Survey at the University of Kentucy, have written a new book on the stones, published by The University Press of Kentucky: Kentucky Agate: State Rock and Mineral Treasure of the Commonwealth.
The book defines agates as quartz of the variety chalce dony that are glasslike round nodules containing banded, variegated coloring "often reminiscent of the concentric rings of a tree." Agates "can range from as small as a marble to as large as a basketball," the book says.
McIntosh, who graduated from UK with a degree in philosophy, sells agates near his Powell County tomatoes at the Lexington farmers market, at a fruit and vegetable stall fragrant with the sweetish scent of pawpaws.
The "raw" agates soak in plastic tubs — otherwise, they tend to dry out. The finished ones, brilliantly glossy (those with a strip of red are particularly prized) sit on a velvet background nearby.
"This was from between 225 and 250 million years ago," McIntosh said, gesturing at several of the agates. "When I cut it open I'm the only person who's ever seen what I just saw."
Agates are not simply about beauty; they are also marvels of science. Agate specialists such as McIntosh discourse knowledgeably on such terms such as "fortification" banding and botryroidal formations (bubbles).
McIntosh has spent three decades wading in creeks and walking on hillsides seeking rocks. Most of the wandering has been done on private land, where he finds owners "just happy to get rid of the rocks."
The finished stones can cost anywhere from $30 to $250. Lexington jeweler Rachel Savané uses them for some stunning pieces. Get a look at Savanesilver.com.
"When I look at the pile of gems and my hand lands on one in particular, I feel myself gasp," said Savané. "And that means you may as well set it aside because this one's going home with you. It's already decided."
Agates have been used for decoration for thousands of years, a common material in carvings found in ancient sites and for such new age uses as providing proper feng shui flow in houses.
At the farmers market, McIntosh picks up a greenish-gray piece called moss agate. In one rock, the center is quartz, translucent in places, with agate on the outer edges.
"There are so many variations in the patterns that make them unique," McIntosh said.
He hopes that his collection eventually will be available to more people than now see it at the farmers market or while shopping for jewelry. He wants his agates to be in a museum. Science can make synthetic diamonds, he said, but not synthetic agates.
"When you get a gemstone out of agate, you've got something unique," he said.
From Roland McIntosh's book with Warren Anderson, Kentucky Agate: State Rock and Mineral Treasure of the Commonwealth (University Press of Kentucky, $45): "Kentucky agate has been known for many years. Early inhabitants of the area used pieces of red and black agate as decorations along pathways and as borders around gardens. Some agates were stacked in piles while gardens and crops were prepared.
"It was not until the early 1970s that agate became a valuable and rare collector's item. At this time collectors exploring in the area of the Middle Fork of Station Camp Creek in Estill County picked up some gravel deposits and saw red and black agate fragments. Once their beauty and potential were recognized, more collectors began to search for these beautiful rocks. Soon the word spread, and by the mid-1980s numerous collectors were searching parts of Estill, Powell, Jackson, Menifee, Madison and Lee counties for Kentucky agate."
Cheryl Truman: (859) 231-3202. Twitter: @CherylTruman.