Island Excursion
Glowing rocks add sparkle to garden gala

By Catherine E. Toth
Advertiser Staff Writer

Eric DeCarlo, associate professor in oceanography at the University of Hawaiii-Manoa and vice president of the Rock and Mineral Society of Hawaii, holds a fluorescent rock found in Morocco. The rock and mineral society will display a number of glowing rocks at Saturday's Midsummer Night's Gleam at Foster Botanical Garden. Kyle Sackowski • The Honolulu Advertiser Midsummer Night's Gleam 4:30 p.m. Saturday Foster Botanical Garden, 180 N. Vineyard Blvd. Free 522-7060, 537-1708 Also: Alcohol and animals are not permitted into the park. Although Simply Ono will operate a lunch wagon in the parking lot, people can bring in their own food.

Take a moment to think that over.

The terms "rock" and "glow" can seem as unlikely a combination as "beer" and "milk." But some minerals exercise their glowing powers in the right atmosphere: under ultraviolet or "black" light.

That makes the exhibit a perfect addition to the annual Midsummer Night's Gleam at Foster Botanical Garden Saturday.

Along with lantern-lit trees and pathways that make the evening so magical, the Rock and Mineral Society of Hawaii (Hui Pohaku O Hawai'i) will display a collection of fluorescent minerals that, under varying frequencies of black light, will energize in colors of red, blue and green.

"This is the perfect way to show these fluorescent rocks," said Nathan Wong, recreation specialist with Foster Garden and rock enthusiast. "The colors just flash."

Fluorescent minerals, such as certain types of calcite and fluoride, react to ultraviolet light, which "excites" the electrons in the mineral and causes the glowing emission of light.

"It's like the psychedelic days of the '70s," said Eric DeCarlo, associate professor in oceanography at the University of Hawai'i-Manoa and vice president of the rock and mineral society. "All these really bright colors — reds, yellows, blues, white — it's pretty incredible."

The transition from lame to lustrous is one reason Wong, who is organizing the event, scheduled the rock display.

"I just love sparkly stones," he said. "Shiny things — they're so nice to look at."

Especially on Saturday night.

Every summer, Foster Garden throws the free evening gala that lures about 2,000 people to witness the beauty of nature. About 3,000 luminarias transform the gardens into something magical, something straight out of a storybook. As night falls, the paper-bag and candle lanterns resemble twinkling stars, peeking from the trees the garden is known for.

One tree in particular fits the magical scene. The cannonball tree (Couroupita guianensis), with its large woody fruits and fleshy pink flowers, is a conversation piece. Out of its trunk coil long tendrils like an octopus. The squatty tree will be illuminated that night, accentuating the large cannonball-sized growths extending from its trunk.

"When I give tours, the kids call it the 'man-eating tree,' " Wong said. "And at night, it'll give you that feeling, too."

The celebration of summer is also a gathering of cultures.

Traditional hula shares the spotlight with Middle Eastern belly dancing. The koto and shamisen ride the winds with Andean pan flutes. Kwan yi fortunes meet tanabata wishes.

Fitting, with lifeless rocks glowing beside night-blooming flowers. "This is Hawai'i, after all," Wong said.