Page 52 - Curriculum Visions Dynamic Book

Moon soil and Moon rock
As mentioned on page 46, the Moon’s surface appears to be made of dark and light rocks. The maria are dark and contain lavas. Their darkness is due to the large amount of iron in the minerals of the rocks. The brighter highlands are also made of molten rocks, in this case a kind of granite with fine crystals.
Many of the rocks are made of large sharp-edged fragments, which must have been formed by the building up of materials thrown from impact craters. The most likely way this could have happened is if a later impact fused together the broken rocks of a previous impact.
The Moon cannot have a true soil because it would have to be a mixture of rocks and living tissue. On
the Moon “soils” are mainly dustlike and are the broken-down remains of rocks alone. In this case, with no water to break up the rocks as on the Earth, fragments have been produced during impacts
by tiny meteorites. One result of rocks breaking by impact is a large proportion of glassy particles in the “soil.”
The skin of Moon rocks and soil has one strange
property: It contains fragments of the Sun. That is because the particles of the Sun in the solar wind are not trapped in the atmosphere as they are on the Earth, but reach the ground at high speed and embed themselves in the surface materials.
 These orange glass spheres and fragments are the finest particles ever brought back from the Moon. They range in size from 20 to 45 microns and are about the same size as the particles that make up silt on Earth.
The orange particles, which are intermixed with black and black-speckled grains, come from the Taurus-Littrow landing site investigated by the Apollo 17 crewmen.
Chemical analysis of the orange soil material has shown the sample to be similar to one brought back from the Apollo 11 (Sea of Tranquillity) site several hundred kilometres to the southwest. Like it, this material is rich in titanium (8%) and iron oxide (22%). But unlike the Apollo 11 sample, the orange soil is inexplicably rich in zinc. The orange soil is probably of volcanic origin and not the product of meteorite impact.
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