Veins

If your rock has veins, particularly linear ones, it is not a meteorite. Also, if the veins stick out in positive relief, as in many of these rocks, then the rock is definitely not a meteorite because the exposed veins would have been the first things to melt and ablate away as the meteorite passed through the atmosphere. The “stick-out” veins of these rocks occur because the veins are richer than the matrix in quartz, a very hard mineral, and are hence less subject to abrasion and physical weathering than the matrix. This hardness difference leads to “preferential weathering.”

All these rock have veins that stick out in positive relief.. None of these rocks are meteorites.

These rocks are not meteorites.

These rocks are not meteorites. And (did you notice?), none of them have fusion crusts.


Now that I’ve said that, I’ll back off. Some meteorites do have veins of impact melt. These veins are never linear, however. They do not stand out in positive relief as do many of those above. Veins in meteorites are usually about the same color as the matrix of the rock because they are composed of melted rock.

Harper Dry Lake 036 (L6 ordinary chondrite, 85 g). Someone sent me this rock to identify, so I sawed it in two (that’s what we do!). There are prominent veins of impact melt in the interior. All the small shiny bits are grains of iron-nickel metal. Note that these veins were not visible on the surface of the meteorite, as in all the terrestrial rocks above, because the meteorite had a fusion crust.