Q1: I've read that rare jewels can have up to four magical properties. How do these properties stack?
Can the properties be 4 prefix + 0 suffix or 0 prefix + 4 suffix?
Q2: What can not be combined?
Can a rare jewel have multiple properties of the same kind?
For example, both "Tin" (+21-40 To Attack Rating) and "Silver" (+41-60 To Attack Rating) = 62-100
I'm guessing that it is not possible but I would like some kind of confirmation on this.
Q3: If properties of the same kind can be combined, can multiple properties with the same level/name be combined?
For example 2x "Silver" (+41-60 To Attack Rating) = 82-120
Q4: Are there certain combinations of "types" that can not be combined in a jewel?
For example, +% Damage and +Maximum Damage.
Q5: Is "Affix level" the same as required character level?
I did already look there, but this is how I interpreted that page:
Q1: Not answered on the wiki.
"Rare Jewels: Can have up to three prefixes and three suffixes, but none of the "magic only" affixes can occur on Rares. (This may change to 4 total mods, 2 of each, in v1.09.)" This line is from at least 2006 and we're at version 1.13 now, so has it changed?
Q2: Not answered on the wiki.
Q3: Not answered on the wiki.
Q4: Not answered on the wiki.
But unsure if these these numbers are up to date.
A rare jewel can have up to four rare affixes, with up to three prefixes (and one suffix), or three suffixes (and one prefix).
A rare jewel can only have one affix from each group, which this affix calculator displays. Thus the Tin and Silver prefixes cannot be selected for the same rare jewel. Similarly, the Carbuncle (+(1-5) Maximum Damage) and Carmine (+(6-9) Maximum Damage) prefixes cannot be on the same jewel (both group 104), but the of Wrath (+(6-9) Maximum Damage) suffix could be on the same jewel as either, since it's in a different group (14).
Each affix can only be selected once.
No, except for affixes in the same group. However, socketing Jewels with Enhanced Damage and + Min/Maximum Damage in items other than weapons can result in bugs (consult this thread).
No (consult the affix calculator). Originally required level = affix level * 3/4, but since the expansion (which introduced jewels) this no longer applies.