Based on my encounters with people and works so far, I have identified qualities that makes an artist.
Perseverance - An intense work attitude towards accomplishing the task. A little theory or an equation is enough to solve a problem, but practicing this over a large corpus of problems and time constrained testing would produce a quality work when applied in practice. With the incremental and iterative approach, the task is accomplished.
Resilience - The amount of time, strength, and number of attempts, regain from fall, all losing without morale.
Practical - Artists are extremely practical. They know what material people or things are made of, because they've have spent long enough time studying and observing. They know their strength, how much of work they can do, what is impossible...
Understanding of the self - Before anything, they know themselves - their habits, mood cycle, impatience, thoughts, desires.. They are not afraid to be alone with their thoughts.
Long term Training - These people undergo phenomenally long training over years either through schooling or by hard lessons taught by hunger and bureaucracy.
Consistency - They make it perfect the first time, tenth time and every time. Knowing the ingredients and how they interact, artists have a template of actions. One way to achieve consistency, is by writing down - materials, how to work with, timing for various steps in as vivid detail as possible.
Ability to stay silent - One thing an artist learns after an understanding of the art is to know the subtlety of work. They naturally will become humble.
Confidence - Artist is well versed in understanding, its position in its surroundings.