• Rocks can tell us about the history of the earth, either through the fossils they might consist of or contain, or their own physical structure, or what processes occurred to create a particular rock - elements, chemicals, pressure, atmospheric influence, etc... - the deeper you go, the older the rock, most probably, and therefore deep down towards the centre of the earth, there may be answers as to the planet's creation/formation/deeper history, which links back to Astronomy
• Float in space, and help create planets, including Earth. Rocks obtained from the Moon support this claim, due to a 'tiny excess of a heavier variant of the element zinc' - research further
• Entire ecosystems altered due to 'space rocks', eg: the asteroid that destroyed three quarters of life on earth, and ended numerous species and the Cretaceous age (65 million years ago, not 6.5 million) - left the 'Chicxulub crater' (though some argue that the crater it left is not the Chicxulub crater, despite evidence saying otherwise). This also lead to our existence in the long-term
• ^ Marked end of the Cretaceous period and beginning of the Paleogene period. Geologists and planetary geologists refer to this as the Cretaceous–Paleogene boundary (K–Pg boundary)
• Fossils - self-explanatory
• "We are all rocks" - ??????????????? no
• ^ Calcium found in rocks and makes up 3.63% of Earth's crust is also found in human teach. Iron that makes up 5% of Earth's crust is also found in human (and likely other creatures') blood. These elements were created in the interiors of collapsing stars. Humans "made of stars"
• No
• I am not a rock
• Or a star
• That does not even make sense. We consist of some of the same elements, we are "made of stars" in the most rudimental sense. That statement is misleading and confusing.
• The four inner planets of the Solar System (closest to the Sun) are made of rock
• Some markings on some rocks may be able to determine the age of the planet it comes from
• Panspermia - the theory that rocks brought life to Earth (and likely other planets throughout the universe) by way of early organisms, proteins, water, etc... the "building blocks of life"; research in August 2015 supports this claim, showing "evidence that early comet impacts influenced amino acids to change into peptides"
• The Moon is a rock, obviously - perhaps possible to compare Moon rocks to Earth rocks and discover the absolute truth of how the Moon came to be
• Rocks are classed as baryonic matter
• Astronomers measuring the density and composition of the universe using leftover radiation from the Big Bang discovered that the baryonic matter of which rocks belongs to makes up only 4.6% of it - research further
• Rocks made of silicates, rock-forming minerals made of oxygen and silicone, more hydrogen atoms than silicone atoms in the Solar System, so much more hydrogen found than rock. Rock makes up the majority of inner terrestrial planets due to the fact that hydrogen and methane (and ammonia) cannot condense because of the thermal energy closer to the sun. The rocks (the planets' bodies) cannot hold onto these elements, therefore it is the silicates that end up forming the rocks of the inner planets, hence why there are no gaseous planets closer to the sun
• Outer planets also have rock at the centre, just less
• Rocks make good pets? Better than an animal I suppose...
• Rocks made up of all the different minerals in the universe flew together at the beginning of time(? IF the beginning of time was the beginning of the universe, which I doubt) to create the planets
• Rocks dating back to K–Pg boundary period indicate global catastrophe, ie: layer of grayish clay found in all of the K-T boundary era rocks, which contain unusually high concentrations of iridium. As this element is extremely rare in surface rocks on Earth, leading to the conclusion that the rocks were from elsewhere (indicating a large meteorite impact... rocks from space)

• Shiny black crust on meteorites as a result of going through the Earth's atmosphere
• Meteorites potentially heavier than normal Earth rocks due to their contents
• Meteors give off a glow due to burning up - down to friction and speed and obviously not magic, duh
• Hoba meteorite - largest known, found in Nambia, 60 tonnes, discovered in the 1920s, believed to have impacted approximately 80,000 years ago
• Asteroids can have their own moons (for example: the 19 mile wide Ida, which has a 1 mile wide moon, Dactyl)
• Some asteroid considered to be dwarf planets - Ceres, Pluto, etc
• None of these are to be confused with comets, which are something else entirely
• "Meteor showers are Earth's way of getting clean" ??????????????? - research further
• Meteorites can be as small as particles, specks of dust, grains of sand - as long as it is bigger than an atom, and smaller than an asteroid, it counts
• Asteroids are considered 'minor planets' (essentially any astronomical object that orbits the Sun but is not one of the 'official', 'main' planets nor originally classified as a comet - includes asteroids, dwarf planets, and centaurs [obviously the celestial kind, not the mythical creature kind)
• Pluto is a dwarf planet, technically an asteroid though some argue its status as a comet
• Some people wish on what they think are 'falling/shooting stars', but actually they are just meteors. It makes no sense why people would make wishes on falling stars anyway, because they cannot grant them. Making wishes does not work.
• Asteroids sometimes travel in groups
• The largest known asteroid is as large as the state of Texas in the United States, and it is 582 miles across

The largest rock ("Dwayne Johnson", apparently)

The only difference was that each rock is a different size. They were all released from the same height, at the same time, and fell at what I presume is the same velocity, it is true that the only magic used on them was that which stopped them from being suspended in the air/caused gravity to take hold. You could also argue that the rocks were all released and fell to the sand in different places, even though they were near each other. Though this may not have caused any significant difference, it should still be factored in, in case of some sort of strange gravity anomaly/pocket in the classroom, which may potentially have caused one of the rocks to slow down and lose velocity

Firstly, it should be noted that the weight of an object does not affect how fast it falls to the ground; different weighted objects will fall to the ground at the same speed. Therefore we know that it was not speed or velocity that influenced the sizes of the craters. The only other (significant) variable is the size (mass) of the rocks. Given that the rocks are all different sizes, and so are the craters, if you apply this experiment to meteorites and Earth the most probable answer is that the higher the mass of the meteorite (rock), the larger the resulting crater will be. There could potentially be other factors, however, other than just mass.

Dropping the rocks (which are all the same mass) from three different heights lead to their creating three differently sized craters. The rock dropped from the lowest height left the smallest crater, in terms of diameter, and the rock dropped from the highest height left the largest crater, in terms of diameter

Yes

The first experiment showed that rock with the bigger mass left a larger crater despite being dropped from the same height as the others. The second experiment showed that a rock with the same mass as its competitors could create a larger crater if dropped from a higher point. I think that proves that both factors play a role in the size of the crater, and as it is difficult to tell precisely the difference in the size of the craters versus the size of the rocks versus the precise heights from which they were dropped, using only the vague results from these experiments we can't say for sure which factor has more influence on the size of the crater. "Dwayne Johnson" might create the same size crater that "Kunzite" would create from an even greater height. But if you add height and velocity to "Dwayne Johnson" the crater would be even larger, so velocity can add even more of an impact and create an even larger crater.