There are rocks from the Moon, rocks from Mars — and now, just maybe, a rock from Mercury. But now, for the first time... you can own your very own piece!
Some scientists say that this is a piece of Mercury and is consistent with observations of the small planet's surface, but other scientists argue that the meteorite is too old to be from Mercury. The age of the meteorite is 5.46 BILLION YEARS OLD! That would have been almost immediately after our solar system sprang from the swirling disk of gas and dust around our newborn sun (can you imagine?!). The tight time frame means that the then proto-Mercury would have had only 8 million years to form, melt inside and separate into core and crust before another impact knocked off a chunk of its outer layer. That said, that’s not an impossible scenario . So overall, this is inconclusive. BUT one thing is for certain... even if this isn't from Mercury, it isn't from any other planet in our solar system... so where did it come from?!
Physical Characteristics: A group of 35 very fresh, dark greenish stones (total 345 g), several of which have partial remnant chartreuse-colored fusion crust. This material is notable for the characteristic "frosty" luster of the plagioclase and bright green color of the clinopyroxene.Petrography: (A. Irving and S. Kuehner, UWS): The studied specimen has an overall plutonic igneous (possibly cumulate) texture. It is a medium-grained aggregate of Al-Cr-bearing diopside, calcic plagioclase and lobate (possibly resorbed) grains of forsterite, with accessory Cr-bearing iron sulfide (probably troilite), very sparse ferrochromite, kamacite and taenite, and rare eskolaite (associated with Cr-Fe sulfide). In thin section the untwinned plagioclase is birefringent, but the levels of birefringence are less than normal and variable on a fine scale (suggesting the existence of compositional and/or structural microdomains); there also are sparse vesicles (suggesting at least partial melting). The pyroxene exhibits at least two sets of polysynthetic twin lamellae, which resemble those produced by moderately high shock.
Geochemistry: Clinopyroxene (Fs1.1-2.6 Wo45.1-44.5, FeO/MnO = 12-21, Al2O3 = 2.6-2.8 wt.%, Cr2O3 = 1.0 wt.%), plagioclase (An88.1-89.2Or0.0), olivine (Fa2.7-2.8, FeO/MnO = 30-36, CaO = 0.27-0.32 wt.%, Cr2O3 = 0.32-0.35 wt.%). Bulk composition (G. Chen, UAb): analyses of representative bulk wire-saw cutting dust by ICP-MS gave: (in ppm) La 0.15, Ce 0.34, Nd 0.16, Sm 0.05, Eu 0.58, Gd 0.05, Hf 0.44, Th 0.27. Oxygen isotopes (K. Zeigler, UNM): laser fluorination analyses of acid-washed subsamples gave, respectively δ17O = 3.214, 3.670, 3.249; δ18O = 7.566, 8.204, 7.957; Δ17O = -0.781, -0.662, -0.952 per mil [for TFL slope of 0.528].
Classification: Achondrite (ungrouped). The combination of highly magnesian mafic silicates and highly calcic plagioclase with chromium-bearing sulfides is unique among achondrites, and the specimen is highly depleted in most trace elements.