Weathering, erosion and corrosion
Some people may aspire towards advanced APT driven by a bit of an obsession with power force and persistence (perhaps even to a worrying degree).
Well there are places where this properties are really needed to make something ven possible (rockets) but much more often desired than maximal strength and durability is deliberate weakness and ephemerality. Mechanical weakness "erosion" (intended breakage points) and chemical weakness "corrosion".
- Think about all those drinking bottles cans and food packaging carelessly tossed wherever they got emptied.
- There's also clothing that should better rip if loaded too strongly (getting tangled in a passing vehicle or a machine).
Its always good to try to avoid spill of artificial material that is foreign to nature as much as possible. (Side-note: artificiality does not necessarily imply foreignness to nature). But archiving a perfect prevention of all spill on a global scale will always remain impossible.
To prevent spill from accumulating in and polluting an sensitive pats of earth's nature its best when the spill decays in a certain timespan.
So the many gemstone like compounds that are somewhat/slightly soluble even in pH neutral water are very useful.
Gemstone based compounds usually are not biodegradable since there usually are no hydrocarbons involved that can be eaten. The elements involved can be more or less bio-compatible though (salts, acids and bases all diluted enough to not be problematic). (Bio-activity carrying away freshly solvated material speeding up diffusion??)
It can also be ok if materials leech out more problematic elements like e.g. boron and chlorine as long as this happens slowly enough.
One can make a chart: water/rain solubility vs bio-problematicness of contained elements.
Really rapidly dissolving compounds (at the level of NaCl) need to be devoid of problematic elements or only be present in minute amounts. Also they need to be sealed in o less soluble shell. Otherwise the product would be very short lived.
- The structural housing matrix of AP products should be less soluble than dispersed particular or fibrous content. Otherwise the particular or fibrous content may be spilled and cause problems.
- surface degradation and functionality breakdown point ... (TODO: elaborate on that)
Gemstone based compounds usually do not oxidize (rust) since they are already maximally oxidized. but other forms of corrosion may occur if the combination chemical aggressiveness and exposer time is big enough.
Gemstone based metamaterials extend the range of outdoor weathering resistant materials enormously.