Lumahai Beach, Kauai, Hawaii
Bright green olivine is a significant mineral in Hawaii's slow-flowing basaltic lava and is rich in iron. Its density allows it to separate from other sand grains in the rolling and depositing action of waves, which results in the accumulation that tints this beach a yellowish green. Dense sands like olivine are also resistant to weathering, allowing it to endure millennia of constant waves. (Magnification 110x)