i highly doubt the area where you mine dictates the odds of your success, its just a roll of the dice.
so here is the part of the source code that determines your luck of finding ore. However i am not sure, that it is the very latest code used in the recent release, but as it appear luck depends on
skill, item quality (which tool you use), and the distance from the center of recource (so the place actually matters)
Good luck
float roll = psserver->rng->Get();
// Calculate factor for skill
float f1 = event->dependency->GetCharacterData()->GetBaseSkill((PSSKILL)event->nr->skill->id);
f1 /= event->nr->skill_level;
// Calculate factor for item quality
float f2 = event->dependency->GetCharacterData()->GetItemInSlot(PSCHARACTER_SLOT_RIGHTHAND)->GetItemQuality();
f2 /= event->nr->item_quality;
// Calculate factor for distance from center of resource
csVector3 diff = event->nr->loc - event->position;
float dist = diff.Norm();
float f3 = 1 - (dist / event->nr->radius);
printf("Probability: %1.3f\n",event->nr->probability);
printf("Skill Factor: %1.3f\n",f1);
printf("Quality Factor: %1.3f\n",f2);
printf("Distance Factor: %1.3f\n",f3);
printf("Total Factor: %1.3f\n",event->nr->probability * f1 * f2 * f3);
printf("Roll: %1.3f\n",roll);
if (roll < event->nr->probability * f1 * f2 * f3) // successful!