The case for (and against) a rock from Mercury
There are rocks from the moon, rocks from Mars — and now, just maybe, a rock from Mercury.
In early 2012, a nomad in the western Sahara spotted some green stones scattered on the sand. Knowing that the empty desert was a good place to find rocks from space, and that meteorite dealers would pay good money for them, he picked up about three dozen that looked related.
By spring all 345 grams of them were for sale in Erfoud, Morocco. Stefan Ralew, a meteorite dealer from Germany who was cruising the markets, spotted the stones and asked about them. The seller said he thought they were from a Martian meteorite. But Ralew argued that they couldn’t be from a meteorite of any type because of their bizarre, lustrous, emerald color.
Thus began a scientific detective story to