Caption: Porous chondrite interplanetary dust particle.

"This is a scanning electron microscope image of an interplanetary dust particle that has roughly chondritic elemental composition and is highly rough (chondritic porous: CP). CP types are usually aggregates of large numbers of sub-micron crystallites (grains), clustered in a random open order." (Somewhat edited.)

Note that chondrites are meteoritic material that has been mostly chemically unprocessed since the solar system formation. They are rich in silicates: i.e, silicon and oxygen like most ordinary rock. There are other elements and compounds. Note that chondrites are NOT ordinary rock.