continuing from here!
Yes, olivine, peridotite, and ringwoodite are all three found in meteors and asteroids! olivine seems to be particularly common, since olivine just needs the super-high heat to form, rather than heat AND pressure like peridotite, ringwoodite, and diamond. those kinds of temperatures occur all over the place in outer space, like meteor collisions, protostar formation disks, and planetary tectonics. the protostar formation disks in particular are important, because that explains how olivine ends up in comet trails. basically, if you’ve got enough heat and pressure to form an iron-nickel meteorite, and you’ve got enough of the right elements, you’ve got enough heat and pressure to form olivine!
you get ringwoodite by shoving olivine and water beneath around 14 gigapascals of pressure and set it to 800 degrees Celsius, which doesn’t really happen on smaller scales except for shock metamorphosis in instances where two olivine and water-bearing asteroids hit each other head-on. The presence of ringwoodite in the earth’s mantle means that it’s likely that there’s a LOT of water beneath the crust- up to three times the total surface amount, including the ice caps!