Kevin Lew is spoiling things for everyone. He is 2 for 2 now in correctly guessing that the answer to Contest #4 is the Green Sand Beach on the Big Island of Hawaii.
The green in the green sand is the mineral olivine, which can be found in the volcanic rocks in Hawaii. The beach is very difficult to get to as there are no roads, no signs, and you have to climb down to get to the beach. It is the only one of its kind in the world.
I thought this one would take longer to solve. The gauntlet has been thrown….