Back to our adventures on the Big Island! While there I had the bright idea to visit a green sand beach, which can only be accessed by foot or very serious 4 wheel drive. No problems, Case walks over a mile to and from school every day. We figured it would be worth it, as there are only two green sand beaches in the world. The other one is in the Galapagos, and hence even harder to reach.
The directions we received were a bit vague. I read between 1 1/2 and 2 1/2 miles. Having done it myself, I'm guessing it was closer to 2 1/2. Case was not really happy with the distance, but marched along pretty well.
When we reached the cliff overlooking the beach though it was stunning. The ocean was ridiculously blue and clear.
We hiked down the cliff and dove in. Case found a snail and parked himself in the glittering crystal sand.
See how green the sand is? It was actually slightly more green in person.
The visitor center at Hawaii Volcanoes National Park says that the lava there is unusually rich in olivine. Olivine is present in most lava, and like most lava, the rocks on land there are black, but if you look closely you see very small flecks of green. Olivine is green due to the presence of iron and magnesium, which makes it tougher and more dense than the rest of the rock. When the lava here breaks down the less dense silicate materials are washed away more quickly, causing the olivine crystals to build up on the beach.
When olivine crystals are large enough they are known as peridot. These crystals were pretty tiny, but quite striking when you have an entire beach made of them.
