Regmaglypts are shallow, thumbprint-like depressions on the surface of larger meteorites that are formed by preferential local ablation of material from the surface as a meteor passes through the Earth’s atmosphere. They are probably formed by vortices of hot gas. Any meteorite with regmaglypts will have a fusion crust. Many meteorites with fusion crusts do not have regmaglypts, however.
Here are photographs of a few examples. (I collect meteorite photos and do not remember where I obtained some of these photos.)
All the photos below were sent to me buy people who thought the rocks had regmaglypts. None of these rocks are meteorites – none has a fusion crust. Some terrestrial processes lead to rocks depressions that can look very much like meteorite regmaglypts. Most of these features are the result of sculpting by wind or water on Earth. Some of the depressions are incipient vesicles. Preferential weathering occurs when softer material weathers away before harder material. This process seems to occur most commonly in sedimentary rocks. Another process is “plucking” in which rounded clasts fall out of a softer matrix leaving a rounded depression. I’ve seen photos several rocks that appear to be mostly quartz or calcite and that appear to have been preferentially etched by saline solutions solutions leaving a regmaglypt-like surface. The light-colored rock at the top center of the last mosaic below is a good example. (If someone knows more about this than me, please let me know.)
If there is no fusion crust, then the depression is not a meteorite fusion crust.