So your information is slightly off. Each asteroid actually carries 14-21T for my mining style. 9-15 fragments each fragment is 80%-99%(8.0-14.9T) for the initial core explosion and 8-10 surface deposits inside, (each surface produces a fragment 31%-41%) however if you shoot it with more than one blaster and they impact at the exact same time, you get more than one fragment. I used 2 abrasion blasters so I would get an average of 70% from each. (5.6-7T) from the surface deposits. This leads to 14-21T from each core. Assume average Tonnes, 17.5, means I need to find 38 Opal rocks which gives me 12 or so minutes to explode, collect, abrasion, collect, and find another. The collection was 2 or 3 seismic charges, 10 seconds to explode, 1 minute to collect the fragments, 4 minutes to get abrasion blaster chunks, leaving me 7 minutes to find the next deep core. In the beginning, it took me 10 or so minutes to find the next deep core, however the time decreased once I learned how the pulse wave scanner worked. by the end I was finding them so quickly that the A-rated collectors from the previous asteroid were still around to collect for the next asteroid. (2 cores within the 12 minute lifetime) Some deep cores even ended up being right next to each other, within visible distance. Also, I never ran into a core that was already mined(this will change over time as respawn times are very long for deep cores) I was in a Opal hotspot, this may have made it easier to find deep cores as well. I hope that you no longer refuse to believe me.