R3.8, Member of a rare group of chondrites, formerly named the Carlisle Lakes group, after a meteorite found in Australia in 1977. It is now named for the type specimen Rumuruti that fell in Kenya, Africa, in 1934. Rumuruti is the only witnessed fall of this group and only one small
Purchased August 1, 2001
coordinates not recorded Three fragments weighing together 722 g were purchased in Erfoud, Morocco. Classification was performed at UCLA, and Northwest Africa 978 was determined to be an R3.8 Chondrite meteorites are the most common accounting for 83.6% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), free Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such Click on Term to Read More. Although it was initially assigned a relatively low weathering grade of W2, a more useful weathering index (wi) has since been developed by Rubin and Huber (2005) for those Oxidation and reduction together are called redox (reduction and oxidation) and generally characterized by the transfer of electrons between chemical species, like molecules, atoms or ions, where one species undergoes oxidation, a loss of electrons, while another species undergoes reduction, a gain of electrons. This transfer of electrons between reactants Click on Term to Read More Work in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and Click on Term to Read More groups lacking significant FeNi-metal phases, such as the CK and R chondrite groups. This index is based on the modal abundance of brown-stained silicates as visually determined on a Thin slice or rock, usually 30 µm thick. Thin sections are used to study rocks with a petrographic microscope. in transmitted light at ~100× magnification. It is thought that the brown staining in R Chondrite meteorites are the most common accounting for 83.6% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), free Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such Click on Term to Read More (and CK chondrites) is caused by the terrestrial decomposition and mobilization of sulfides (mainly Iron sulfide group of minerals whose composition ranges widely between its end members pyrrhotite (Fe7S8) whose crystal structure is monoclinic, and troilite (FeS) whose crystal structure is hexagonal. Its general formula is Fe1−xS (where x = 0 to 0.17). The troilite phase is found mainly in meteorites and in the Click on Term to Read More and Fe-Ni sulfide, (Fe,Ni)9S8, that is often associated with troilite, and found in the matrix and chondrules of CO, CV, CK and CR chondrites. The color is yellow-bronze with light bronze-brown streak and metallic luster. It typically forms during cooling of magmatic sulfide melts during the evolution of parent silicate melt. The Click on Term to Read More), which are typically prevalent in this meteorite group; e.g., Rumuruti wi-0 contains 8.0 wt% sulfides. Northwest Africa 978 was determined to have a weathering index of wi-5, or severely weathered. This meteorite has been weakly shocked (S3).
Photo courtesy of Mike Farmer—Mike’s Meteorites and Tektites
click on image for a magnified view
Photo courtesy of Peter Marmet