In their follow-up of this report, a more refined O-isotopic analysis was conducted by Greenwood et al. In another study investigating the close O-isotopic relationship between main-group pallasites, mesosiderites, and the HED clan, Ziegler and Young (2007) discovered that non-homogenized samples of main-group pallasite olivines exhibit a bimodality in 17O values, which also distinguishes their origin from that of the mesosiderites and the HED clan. (2013) determined that a clear distinction exists, thus demonstrating that these meteorite groups originated on separate parent bodies. In a high precision comparative analysis of the oxygen three-isotope composition between olivines from five main-group pallasites and representative HED samples, including eucrite and diogenite material, Jabeen et al. Previous O-isotopic analyses for main-group pallasites and the HED meteorites indicated that these two groups have values that are very similar. Notwithstanding its similar chemical composition to that of the main-group members, Seymchan is an anomalous pallasite due to its high Ir content (van Niekerk et al., 2007). With knowledge of the existence of a pallasitic structure in Seymchan, and of its identical chemical composition to the original Seymchan iron masses, an O-isotopic analysis was conducted the values plot within the field of the main-group pallasites. This heterogeneous mixture, including portions composed of only FeNi-metal and portions containing silicates in a pallasitic texture, is similar to the ironВ–pallasite mixtures found previously in both the Brenham and the Glorieta Mountain pallasites. Remarkably, many of the new masses (~20%) were found to contain silicates with a pallasitic texture, something not discovered previously during studies of only small sections of the original mass. Kachalin found additional masses having a combined weight of ~50 kg. Wang (1986) found that Seymchan (and another IIE member, Lonaconing) had many elemental trends that deviated strongly from typical IIE group members, and therefore, Seymchan (and Lonaconing) was reclassified as an ungrouped iron.Дuring a 2004 expedition to the original Seymchan discovery site, D.

Subsequently, a more precise elemental analysis of the IIE iron group members by J. Wasson (1974) and it was determined to be a member of chemical group IIE. The large mass was provided to the Academy of Sciences, USSR.ДЄ small section of the iron was analyzed by J. Markov, utilizing a mine detector, resulted in the recovery of an additional mass weighing 51 kg. In October of that year, a further search of the area by I. The thumbprinted, triangular-shaped mass weighed 272.3 kg. Mednikov, about 150 km from Seymchan, in the Magadan Region of the USSR (V.

Low-О” 17O subgroup (see details on the Imilac page)ДЄs reported by Mednikov (1967), Zvetkov (1967), and Tsvetkov (1969), a large mass was found in a stream bed of the Yasachnaya River (flowing into the river of Hekandue, a left tributary of the river of Jasachnaja) by a geologist, F. SEYMCHAN Pallasite, MG (main-group), anomalous metal composition

This specimen can rightfully be considered an otherworldly crystal ball with crystals of olivine and peridot (birthstone of August).SEYMCHAN PHOTO To display this page you need a browser with JavaScript support. This is a wondrous three-dimensional presentation of a pallasite, revealing aspects of the structure impossible to see in a flat slab. To make a sphere of this size requires a mass nearly three times that of the sphere, given the amount of material lost during the grinding and polishing processes. Most Seymchan meteorites are non-descript, prosaic masses until they are cut to reveal their internal splendor. The first two masses were found in a streambed by geologists in the 1960s. Seymchan meteorites are found in the Magadan district of Siberia - the location of StalinвЂ™s infamous gulags. As might be expected, pallasites are extremely rare and, indeed, they represent less than 0.2% of all known meteorites. Like all pallasites, Seymchan formed at the boundary of the stony mantle and molten iron core of an asteroid that shattered following an impact with another asteroid.