Hawaii’s Mahana Beach Is Blanketed With Olivine Crystals Eroded From Ancient Volcano

August 17, 2021

It's one of the most difficult beaches to access on Hawaii's Big Island, but certainly worth the extra effort. Because when you get there, you'll be walking barefoot on a blanket of sparkling green sand that owes its astounding color to olivine crystals eroded from the belly of an ancient volcano and delivered to the shore by ocean waves.

Mahana Beach on Hawaii’s Papakolea coast is one of only four green sand beaches in the world. The beach sand on the Big Island’s undeveloped southern tip is rich in the mineral olivine (gem-quality olivine is known as peridot, the August birthstone). Olivine is a common mineral component of Hawaiian lavas and one of the first crystals to form as magma cools.

Locals refer to peridot as the “Hawaiian Diamond,” and small peridot stones are sold as “Pele’s tears” in honor of Pele, the goddess of volcanoes. In ancient Hawaiian chants, Pele was described as “She-who-shapes-the-sacred-land,” and her temper was known to be both as abundant and dangerous as the lava.

Those daring enough to take the three-mile hike through lava fields to the remote beach at the crescent-shaped bay of Pu’u Mahana, will be treated to a display of one of nature’s crowning achievements — a green beach that appears surreal against the backdrop of steely grey cliffs, turquoise blue ocean and bright blue sky. (Locals with four-wheel-drive vehicles are also available to shuttle visitors to and from the beach.)

“At sunset, the play of colors against the sand is simply breathtaking,” noted the website to-hawaii.com.

The abundance of olivine crystals filling the beach comes from the eroded cutaway interior of Pu’u Mahana, a volcanic cone produced more than 49,000 years ago by the explosive combination of lava and groundwater.

As tempting as it may be to take home a small sample of the green olivine sand, the practice is illegal and subject to fines as high as $100,000.

Hawaii's Mahana Beach (also known as as Papakolea Beach and the Green Sand Beach) is one of only four "green" beaches in the world. The others are Talofofo Beach on Guam, Punta Cormorant on Floreana Island in the Galapagos Islands and Hornindalsvatnet in Norway.

The official birthstone for August, peridot is one of the few gemstones that occurs in only one color: generally an olive green. The amount of iron in the crystal structures determines the intensity and tint of the green color. Specimens can range from yellow-green through olive green to brownish green. The dark-olive color is the most valuable.

Credits: Mahana Beach image by Wasif Malik, CC BY 2.0, via Wikimedia Commons. Olivine sand by Brian W. Schaller, FAL, via Wikimedia Commons.