(Since Guilder mentioned about High-grade something something previously, might be worth adding in if someone here interested.)
Before we go to the information of the MA, tl;dr Kimberly Mine is a mine located in Cape Town where you can dig gemstone to get stuff like :
Sapphire Gemstone
Garnet Gemstone
Emerald Gemstone
Amethyst Gemstone
Diamond Gemstone
And the rarest among them all,
Platinum Ore
Don't forget that like San Fransisco's gold digging, there is also Large Gemstone as well.
The system is almost identical to digging Gold Nugget in San Fransisco/NA West Coast.
But what makes it different that now you have alternative option rather than convert those gemstones to pure ducats.
In Luanda, there's a NPC "Gemstone Appraisal" just near Port Official, where he can show you production recipe.
The recipe converts those freshly-digged gemstone to either High-grade version (if normal success) or Highest-grade version (if great success).
These High/Highest-grade gemstones later can be used to make something via Florence (Anita).
The same NPC also offers to measure Large Gemstone's 'carats', in which you can use to exchange to some stuff the list offered.
Apparently, he also offers you to measure Large Gemstone either with converting other gemstones to ducats or without. Very generous.
Now back to the MA itself..
This is 8-item MA related to gemstone digging. This MA can takes forever for you to fill, so be prepared to waste more time.
All information about recipe, materials, and etc can be found in respective links.
Jewel Mirror
Platinum Mirror
Jewel Box
Jewel Clock
Jewel Orb
Platinum Brooch
Jewel Pendant
Jewel Necklace
The reward for all the trouble is
Miner's Clothes which gives.. very underwhelming booster, considering all the effort and time..
If you just aim for getting MA rewards then well sure go ahead, but don't mad at me because i already warned you!