Timeline for answer to Is Mohs scale of mineral hardness applicable for rocks and minerals of terrestrial planets other than Earth? by Oscar Lanzi
Current License: CC BY-SA 4.0
Post Revisions
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 14, 2020 at 14:02 | comment | added | dotancohen | Just as we have a cosmic ladder of objects whose usefulness to determine distance have overlapping distances, perhaps materials could be found with overlapping temperature range tolerances to extend the Mohs scales. Talc from 20° to 52°, foo from 45° to 207°, bar from 195° to 538°. So Venusian pyrite would be scratched on a block of bar. | |
| Oct 12, 2020 at 9:31 | comment | added | Oscar Lanzi | Did I not distinguish between interiors and surfaces of planets in the.comment? | |
| Oct 12, 2020 at 9:28 | comment | added | Oscar Bravo | @OscarLanzi A consequence of gravity is pressure. At core of Jupiter, the pressure is so high that metallic hydrogen might exist. This material would just immediately subliminate to gas st STP. | |
| Oct 12, 2020 at 4:38 | comment | added | Nilay Ghosh | It is written here that: "certain types of rock is harder on the surface of the Moon or Mars than it is on Earth, whether it's because the minerals and pressure/temperature ranges are not found or because there are fewer mechanisms allowing deeper rock to rise to the surface". | |
| Oct 12, 2020 at 3:19 | comment | added | user12102 | I've just asked How hard is the hardest ice in the solar system? | |
| Oct 12, 2020 at 1:06 | comment | added | Oscar Lanzi | "Does gravity affect hardness?" How much? Stress from gravitational forces would be very small compared with the stress scale factors (e.g. tensile strength) of a typical mineral, but deep inside the planet it could get big. Compressed material deep inside could well be harder than what we find on a planetary surface. Mineral hardness at STP/NTP is not possible with a material like nitrogen and yet their hardness and strength are important for building geological features on outer solar system bodies. | |
| Oct 12, 2020 at 0:49 | comment | added | aroth | "Thus a distinction must be made between hardness of a Venusian mineral on Venus versus hardness under Earth-ambient conditions." - This can be resolved by stipulating STP/NTP when performing hardness tests. Wonder if a concept of "standard gravity" would also be needed...does gravity affect hardness? | |
| Oct 12, 2020 at 0:38 | history | edited | Oscar Lanzi | CC BY-SA 4.0 |
Chasing typos.
|
| Oct 12, 2020 at 0:29 | history | edited | Oscar Lanzi | CC BY-SA 4.0 |
edited body
|
| Oct 11, 2020 at 22:41 | history | answered | Oscar Lanzi | CC BY-SA 4.0 |