Taking nothing for granite, lawmakers consider endorsing a state rock

Feb. 23—AUGUSTA — Sometimes legislators debate pressing issues such as taxes, housing or highways. Other times, they try to figure out what should be the official state rock.

After weighing the issue, the State and Local Government Committee recently agreed to urge colleagues to pick a state rock for the first time. If it carries the day, that rock will be something few Mainers know much about: granitic pegmatite.

Those who love it, though, say Mainers ought to learn more.

"Pegmatite is the most amazing rock on Earth," Tom Hoffelder of Norway testified. Hoffelder is president of the Oxford County Mineral & Gem Association.

Supporters note the coarse-grained rock is a source of crystals and gemstones, rare elements and some of the prettiest landscapes in Maine.

State Sen. Lisa Keim, a Dixfield Republican, said she introduced a bill to honor granitic pegmatite at the request of constituent Myles Felch, the curator and staff geologist at the Maine Mineral & Gem Museum in Bethel.

Felch told lawmakers that granitic pegmatite "is a very common rock type found in at least 14 of 16 counties, including many of Maine's state and national parks," including Acadia National Park, Grafton Notch State Park and Popham Beach State Park.

But what makes it especially alluring is that it sometimes contains jewels.

Jon Dykstra, a retired geologist who serves as treasurer of the Maine Mineralogical & Geological Society, said the organization is chock full of rockhounds.

"In some states," Dykstra told legislators, "rockhounds focus on hunting fossils, panning for gold or finding metamorphic minerals."

But, he said, in Maine they "have one focus — pegmatites!"

Hoffelder said the proposed state rock is igneous, or stone formed when molten rock, or magma, flows out from earth's hot inner core to the planet's surface.

What differentiates granitic pegmatite from the more common granite is that pegmatite "cools so much slower than granite," which allows "much larger, even gigantic" crystals to form, Hoffelder said.

Robert Gastaldo, the Whipple-Coddington professor emeritus of geology at Colby College, said the reason the rock should be recognized is a simple one: "Maine pegmatites are unique."

"Their distinguishing feature," wrote Edson Bastin of the U.S. Geological Survey in a 1910 issue of The Journal of Geology, is an "extreme irregularity of grain" that can sometimes produce crystals.

"The minerals found in these rocks not only have played a role in our economy," he said, "but will enhance our state's wealth as exploration continues and new deposits are unearthed and brought to market."

The rock is the source for a number of rarities, from the gemstone tourmaline to lithium, a key element in the green economy whose presence is still being explored. One deposit of "a podumene-rich pegmatite on the north side of Plumbago Mountain in Oxford County," Gastaldo said, may be worth more than $1 billion.

State Sen. Rick Bennett, an Oxford Republican, said the tourmalines first discovered in his district two centuries ago kicked off an ongoing mining industry in Maine.

"Areas of my district have become meccas for amateur rockhounds as well as for more commercial actors, having yielded some of the most remarkable gem discoveries in history," he said.

Felch said the tourmaline discovery at Mt. Mica in Paris wasn't even the beginning of granitic pegmatite's importance to the state. By then, it was already sought out in the pursuit of feldspar, a stone used in making porcelain products.

Other minerals also proved commercially useful, he said, including gems from quartz and beryl.

But an astounding find of the lithium-bearing mineral, spodumene, may wind up being the most significant of all. It is a key ingredient for lithium-ion batteries. That makes it "a key element in moving Maine, and the world, into a greener, less carbon-dependent environment," Dykstra said.

Keim said that when Felch approached her about designating a state rock, she was surprised Maine hadn't already picked one.

"After all," she said, "tourmaline was designated as the state gemstone in 1971."

Keim said that granitic pegmatite "seems a perfect fit" for the honor of serving as the state rock.

"It has historical significance to the state," she said, "while at the same time, has the potential to be a critical part of our future."