Agglutinate

Common particle type in lunar regolithMixture of unconsolidated rocky fragments, soil, dust and other fine granular particles blanketing the surface of a body lacking an atmosphere. Regolith is the product of "gardening" by repeated meteorite impacts, and thermal processes (such as repeated heating and cooling cycles).   Click on Term to Read More (photograph below). Agglutinates are small glassy breccias formed when micrometeorites (< 1 mm in diameter) strike the lunar regolith. During micrometeoriteMeteorite so small that it falls to Earth essentially unchanged from how it existed in space. If a meteoroid entering the Earth's atmosphere is sufficiently small (generally less than 10-6 m), it will be slowed by collisions with molecules in the upper atmosphere to a degree where ablation does not Click on Term to Read More impacts, some of the regolith melts and some doesn’t, so the final product is a glass with entrained mineralInorganic substance that is (1) naturally occurring (but does not have a biologic or man-made origin) and formed by physical (not biological) forces with a (2) defined chemical composition of limited variation, has a (3) distinctive set of of physical properties including being a solid, and has a (4) homogeneous Click on Term to Read More and rock fragments. The glass often shows flow features and vesicles (gas bubbles). Impacts liberate solar-wind-implanted H and He in the regolith causing bubbles in the glass. Agglutinates are typically 10s of μm to a few mm in size.