When you want to get a gem of higher quality, you need to try composing several low quality gems into a higher quality one. This is called "gem composing" and it can be done by the jeweler in the marketplace.

Jeweler: (Market 240,256) He is proficient in composing all kinds of gems to upgrade their qualities, but charges a lot of silvers for his services. Various low level gems such as: Phoenix Gem, Dragon Gem, Rainbow Gem, Kylin Gem, Violet Gem, Moon Gem and Fury Gem will be composed into high-quality gems.

How to get a Refined Gem? Prepare 15 Gems from the same sort and pay 10,000 silvers to the greedy Jeweler, and you'll get a Refined Gem.

How to get a Super Gem? Give 15 Refined Gems of the same type and 800,000 silvers to the greedy Jeweler, and you'll get a Super Gem.

How to get a refine Tortoise Gem? Prepare 7 different refined gems of the same type (refined phoenix gem, refined dragon gem, refined rainbow gem, refined kylin gem, refined violet gem, refined moon gem, refined fury gem). Then pay a hefty sum of 100,000 silvers to the Jeweler. You will receive one of the following:

i. 2 Refined Tortoise Gems
ii. 3 Refined Tortoise Gems
iii. 1 Super Tortoise Gem

How to get a Super Tortoise Gem? A super tortoise gem is ridiculously expensive, but powerful nevertheless. 15 Refined Tortoise Gems and 1,000,000 silvers is necessary for composing.