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Santa Rosa

Iron, IC
Found in Boyaca, Columbia, 1810

The main mass of Santa Rosa — at a massive 612.5 kilos — and other smaller specimens, were discovered on a hill in a small town in the Andes Mountains. Other larger individuals were obtained from a miner in a nearby village. It is noted a few specimens were used as anvils. During the 19th century these pieces were distributed, and scientific studies on the meteorite ensued. There was a lot of confusion during the initial studies, because several wrought iron specimens were included as meteorites. In addition, it was deduced that a few specimens appeared to have been reheated (thought due to their use as anvils).

An adventurous gentleman by the name of Henry A. Ward made a long journey to Santa Rosa in an attempt to clear up the mess.

Ward was able to negotiate and purchase the main mass, where it was displayed in the village marketplace on a pillar. Ward wasn’t allowed to export the entire meteorite, he instead took a 150 kilogram end cut, of which part was smooth from the bashing of a sledge hammer. Ward cut up his end and distributed the pieces for continued study.

From 1926-1942 the remaining pieces of this important fall were discovered, and thanks to Ward’s hard work, the final studies of the Santa Rosa meteorite were completed. As described in Buchwald and Wasson’s paper: etched sections are anomalous — displaying no clearly identifiable Widmanstätten structure, the cohenite is decomposed to graphite, the Neumann bands are decorated, numbers subboundaries and partial recrystallization are introduced, and the phosphides display rounded edges and detached taenite islands. In addition, there are troilite-daubreelite-schreibersite assemblages which suggest a high-intensity shock.

Final studies of the recovered masses has left us theorizing about this rare and unusual space rock’s history — there are surprising microstructure variations from specimen to specimen thought to be caused by sustained high heat with temperatures from 500-550° Celsius. These differences are not thought to be caused by artificial reheating, however. As it is unlikely that an anvil could be 500° Celsius for extended periods of time. So alternatives are theorized: the meteorite, while inside its parent body or circling in the cosmos, suffered a decomposition of cohenite at one end while next to nothing happened at the other. Or, the deceleration and rupturing during its flight through our atmosphere was so violent that some of the masses were reheated. And finally, that a shock event that produced the melted troilite was weakened in force in one area, while others were heated selectively and sharp temperature gradients took place around them, causing the bizarre structure.

While Santa Rosa has been known to science for many years and its total recovered weight is significant, it is extremely unusual to see this beautiful and historic iron on the collectors’ market, as most examples belong to research institutions. Santa Rosa is one of only eleven meteorites in the IC class. We have less than five superb part slices of this intriguing meteorite available. Note its exquisite and unique Widmanstätten pattern. Please note that these slices are etched and finished on one face only.