Off the Namibian coast, where the desert winds blow steams of dust out to sea and most of the world's diamonds are found, there's a bright blue hydrogen sulfide bloom in the water.
According to NASA:
A study published in 2009 found that the frequent hydrogen sulfide emissions in this area result from ocean-current delivery of oxygen-poor water from the north, oxygen-depleting demands of biological and chemical processes in the local water column, and carbon-rich organic sediments under the water column. When the hydrogen sulfide gas reaches oxygen-rich surface waters, pure sulfur precipitates into the water. The yellow color of sulfur turns the dark blue water green.
Near the hydrogen sulfide eruptions, multiple, linear dust plumes extend over the Atlantic. Most of the plumes appear to originate from stream channel sediments, and they retain the pale beige color characteristic of such sediments. Wind kicking up dust and pushing it seaward is a common occurrence along the Namibian Coast. Easterly trade winds from the Indian Ocean lose much of their moisture as they pass over the African continent. By the time they reach the Namibian coast, the winds are hot and dry, and they dry out even more as they pass over Namibia's low-lying coastal plain.
Image by Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.