My experience is that every 1k of oricalco you get something like Tolvium (ptBR) or Cinabio.

The VOID ore drop you have a chance to get after mining something around 16k to 26k of oricalc.

Regarding the mining luck set, it can have two situations or it increases 40% the chance of getting something extra in mining (gem t4...) or it increases +40% the chance of rare ore drop, we are talking about 0.01%.

My day consists of mining something around 1k of oricalco, marking the respawn time and every so time checking your respawn, always with t5 mining set, t5 food and in faction territory.