In Metallic rings you find all four occurences of Painit, in Metal rich rings only the cores.
Did you use the Pusle Wave scanner before setting the prospector drones on the bright yellow asteroids?
Scan ring with DSS
Find hotspots.
Visit appropriate hotspot (select one in darkness, e.g. shadow, you see the yellow colors better)).
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Get rid of any lurking pirates
Ping the pulse wave scanner
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Sic the prospector on the very bright yellow ones looking like a teardrop
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If they contain a core, blow them up with the seismic charges.
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Collect the fragments, free any surface sdeposits with the abrasion blaster.
You can also shoot at the fragments with the mining laser, but this usually will not yield the core material.
Repeat
If the storage is full, fly home, do not visit another hotspot, you will
certainly meet pirates then.
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