Sky of Blue and Sand of Green

It’s time for another BLOG POST ABOUT SAND! Yes, sand! One of my favorite recreational geological studies! Just kidding—it’s my #1 favorite recreational geological study!

Papakolea Beach looks greenish (or “British khaki” maybe) because of the high content of olivine. Olivine is a common mineral found in igneous and metamorphic rock. When magnesium rich, silica-poor magma cools, little olivine crystals form. My kids loved the rocks on Chinaman’s Hat because they were all peppered with olivine crystals. Isaac and Elo used their little fingernails to scratch out the crystals, which they present to me as gems. Because they (sort of) are (or could be)! Pure, gemstone-quality olivine is the beautiful, bright green semi-precious peridot, the August birthstone.

But back to Papakolea. This is THE green sand beach on the Big Island, one of four in the world. The moment I first heard about this beach my little heart squeezed with such joy and longing I cannot describe. So Chris and I topped off the world’s most fun day on the Big Island with a 4.5 mile hike out and back to the green sand beach at sunset.

We arrived at Papakolea beach shortly before sunset. We climbed down the embankment as the sun sank rapidly behind the rim. The shimmering olivine absolutely glowed in the last warm rays hitting this stretch of coastline. It was magnificent. The crystals were fine and mostly uniform, interspersed with grains of fine black sand.

Someone with a truck offered us a ride (for money) but we opted to hike back out. The sun set completely, and the wind blew steadily here close to South Point, over our shoulders and away past the islands toward other seas, other hemispheres.

At a BBQ with friends back on Oahu recently I got overexcited about sand and ended up tromping down to a different green sand beach (secret surprise green sand beach No.5!) to show my friend Jackie all the olivine. We got drenched by a wave because we did what you should never do and turned our backs to the ocean. Oops. The green sand beach on Oahu is similarly at the base of a volcanic crater just like Papakolea is, but sand there has a smattering of tiny white coral grains mixed in. Oh man, the first time i realized that was a green sand beach, I was walking along and felt the texture change under my foot. WHAT I thought, bending down to scoop up a handful to investigate. OLIVINE!! Giddy.

The whole country lies behind us—here at South Point we were for a moment the southernmost people in all of the USA! Nothing before us but sea and Antarctica.