Feel free to read through the following thread:
https://www.planetcalypsoforum.com/forums/showthread.php?132510-Mining-loot-analysis
In this thread are some data taken a few years ago, and a subsequent analysis. The data suggest the following:
0. NRF or claim is determined.
1. Loot size is determined based on drop cost and a 'random' multiplier (note this is not usually the loot you actually get). Example, your drop cost 2 PED, with a 1.030 multiplier, so loot size is 2.060 PED.
2. Tax is applied. For the example in a 5.00% tax area, the land owner gets 0.0500*2.060 = 0.1030 PED. Your loot size is now 2.060 - 0.1030 = 1.957 PED. This is still not the loot you actually get.
3. Resource type is determined. Note that resource type could be determined earlier (like step 0.5). Timing of resource determination doesn't really affect this description of taxation and loot value.
4. Your loot size (1.957 PED) is rounded to a whole number of resource units. Example, if you've found gold stone, you will receive either 1 or 2 stones (at 1.00 PED per stone).
5. The rounding is done probabilistically, with more chance given to the number of stones that is closest in value to your loot size. In this case, since 2 stones (2 PED) is closer to 1.957 PED than is 1 stone (1 PED), you are more likely to get 2 stones. However, the chance of getting 1 stone is about 4.3%, with about a 95.7% chance of getting two stones.
6. The probabilities even out, such that if you found an infinite number of gold claims with loot size 1.957 PED, the weighted average of 1 PED and 2 PED loots would be 1.957 PED.
This hypothesis does predict that it is possible to turn a claim into a NRF, if you happen to round down to 0 resource units (may happen for high tt resources).
This hypothesis has not been proven beyond doubt, but it is consistent with the observed data.
There may be other hypotheses that also explain the data, and we might be unable to differentiate between them.
In conclusion, land owner always gets some tax from your claim, and you, on average, get the rest.
Best Wishes,
Noodles