Kritika: The White Knights/Gems

Gems can be sold or 'enhanced'. This is not the same type of enhancement that applies to items. Gem's 'Enhance' refers to combining to gems of the same type (color and level, e.g. Ruby +2) to make one higher level gem. This is a simple process and only requires two like gems and some gold. With a gem level of +5 or higher, enhance success rates begin to drop. If an enhance attempt fails, the second gem used will be destroyed.

Gem effectiveness is related to stat effectiveness. Regardless of CP, you should focus on maximizing your stats in this priority:
 * Best gems
 * 1) Add'l Damage (Amethyst)
 * 2) Damage Reduction (Peridot)
 * 3) ATK (Ruby)
 * 4) Critical Rate (Onyx)
 * 5) HP (Topaz)
 * 6) MP (Sapphire)
 * 7) DEF (Emerald)

Gems give CP based on the enhance level of the gem, plus a multiplicative bonus possibly based on your level or base stat. Since the CP of, say, a Sapphire, increases with your level, and its bonus is not multiplicative like a Amethyst, then the CP calculation formula must be based on something else. For example, it could actually based on your total stats, rather than just the bonus of each individual item (which would make it easier to calculate). Note that the CP values below may show a range. This is because they were re-tested with different stats to produce a different CP difference. The thing to keep in mind is the difference between grades. E.g. the difference between grades 6 and 7 is often the same as 1 to 2. Thus, if you have two Amethysts equipped, it is best to wait until a third gem of the same enhance level can be formed before enhancing. This way, you will not lower your stat bonus. For example, if you have two level 5 Sapphires, you will get +5356 MP, but if you upgrade one to a +6, and you only have another +3 or lower, your total will go down to 5061 or lower. If you had a 4 and a 6, you would be slightly higher than than two fives (this is the threshold for when you should enhance).
 * CP calculation

Amethyst
Add'l damage +% (CP is based on your base ATK; since this multiplies it, the CP will increase proportionately as your base ATK increases)
 * +0: 4.00%, 1823 CP
 * +1: 4.5%, 2278 CP
 * +2: 5.00%, 2506 CP
 * +3: 5.50%, 2220-2506 CP
 * +4: 6.00%, 2734 CP
 * +5: 6.50%, 2961 CP
 * +6: 7.00%, ?? CP
 * +7: 7.50%, ?? CP

Emerald
DEF +
 * +0: 244, 150 CP
 * +1: 378, level 10, 232 CP
 * +2: 470, level 10, 289 CP
 * +3: 585, level 10, ?? CP
 * +4: 729, level 10, ?? CP
 * +5: 907, level 10, 548 CP
 * +6: 1129, level 10, 682 CP
 * +7: 1378, level 10, 846 CP

Onyx
Critical Rate +
 * +0: 713, 438 CP
 * +1: 1105, 678 CP
 * +2: 1368, 840 CP
 * +3: 1711, ?? CP
 * +4: 2124, 1132 CP
 * +5: 2645, 1409 CP
 * +6:
 * +7: 4014, 2463 CP

Peridot
Damage Reduce +% (208 CP gain per +1; 416 CP gain per 1.00%)
 * +0: 4.00%, 1729 CP
 * +1: 4.50%, 1945 CP
 * +2: 5.00%, ?? CP
 * +3: 5.50%, 2288 CP, level 10
 * +4: 6.00%, 2496 CP, level 10
 * +5: 6.50%, 2644-2809 CP, level 10
 * +6: 7.00%, ?? CP
 * +7: 7.50%, ?? CP

Ruby
ATK +
 * +0: 300, 368 CP
 * +1: 465, 571 CP
 * +2: 579, 711 CP
 * +3: 722, 888 CP
 * +4: 900, 1105 CP
 * +5: 1119, 1374 CP
 * +6: 1395, 1712 CP
 * +7:

Sapphire
MP +
 * +0: 720, ?? CP
 * +1: 1116, ?? CP
 * +2: 1389, ?? CP
 * +3: 1728, 530 CP
 * +4: 2145, ?? CP
 * +5: 2678, ?? CP
 * +6: 3333, 952-1023 CP
 * +7:

Topaz
HP +
 * +0: 629, 93 CP
 * +1: 1484, 219 CP
 * +2:
 * +3: 3119, 460 CP
 * +4:
 * +5: 6648, 979 CP
 * +6: 10,026, 1476 CP
 * +7: