Ozona Texas meteorite thin section microscopy Leitz Laborlux 161117

Second light for the Leitz Laborlux 11 microscope today was to image my thin section microscopic slide of a meteorite fragment from Ozona, Texas. All images using Bresser MikrOkular camera – there is no polarisation in these images as the Laborlux 11 version I have does not have polarised filters.

The information supplied with the thin section states that the Ozona meteorite was found in Crockett County, Texas, USA, in 1929. There were several pieces weiging a total of 127.5kg. It is a classic H6 Chronite. My sample has come from the Michael Cottingham Meteorite Collection.

Andy

Information on chrondrites:

The following information on Chrondrite meteorites comes from Wikipedia. Chondrites are stony (non-metallic) meteorites that have not been modified due to melting or differentiation of the parent body. They are formed when various types of dust and small grains that were present in the early solar system accreted to form primitive asteroids. They are the most common type of meteorite that falls to Earth (around 85% of all meteorites). Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of organic compounds, the origin of life or the presence of water on Earth. One of their characteristics is the presence of chondrules, which are round grains formed by distinct minerals, although the proportion of the meteorite that is composed of chrondrules varies considerably – they normally constitute between 20% and 80% of a chondrite by volume. Chondrites can be differentiated from iron meteorites due to their low iron and nickel content. Other non-metallic meteorites, achondrites, which lack chondrules, were formed more recently. Chondrites are divided into about 15 distinct groups on the basis of their mineralogy, bulk chemical composition, and oxygen isotope compositions. The various chondrite groups likely originated on separate asteroids or groups of related asteroids. Each chondrite group has a distinctive mixture of chondrules, refractory inclusions, matrix (dust), and other components and a characteristic grain size. Other ways of classifying chondrites include weathering and shock. Chondrites can also be categorized according to their petrologic type, which is the degree to which they were thermally metamorphosed or aqueously altered (they are assigned a number between 1 and 7). The chondrules in a chondrite that is assigned a “3” have not been altered. Larger numbers indicate an increase in thermal metamorphosis up to a maximum of 7, where the chondrules have been destroyed. Numbers lower than 3 are given to chondrites whose chondrules have been changed by the presence of water, down to 1, where the chondrules have been obliterated by this alteration.

The information from Wikipedia above there places the Ozona meteorite (as a classic H6 Chrondrite) in the category of Ordinary Chrondrites. Being H6, the chrondrules are less distinct than in some other meteorite thin sections in my collection.

Some features you may wish to look out for in my pictures below are variations in colour in the mineral content, orientation of mineral crystals in same direction (seen particularly in one of the high magnification images), very dense opaque material between the mineralised areas (?iron), areas with larger and others with small mineral crystals, and the shapes of the crystals in the high magnification images.

x4 objective:

x10 objective:

x40 objective:

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