Patanjali describes the attributes of a purified chitta,
Paramanu Parammahattvaantah Asya Vashikaarah
Paramanu: From the minutest
Parammahattvaantah: To the largest in magnitude (are in)
Asya: Of this (chitta)
The minutest of the minute and the largest of the large subjects are in complete control of this (purified chitta).
When the chitta is free of impurities, it gains control over every aspect of Creation from the subtlest of the subtle to the grossest. Whatever the sadhak puts his/her mind to, it gains complete mastery over it. There is nothing which is out of reach of such a chitta.
A direct understanding of the impurities in your chitta can be gauged by looking at your attachments. The more the attachments, the more impure is the chitta and the higher the degree of attachment, the higher the level of impurity. An impure chitta can never give a spiritual experience as you are tied.
Patanjali further describes the qualities of a chitta whose vrittis have weakened due to the practices mentioned in earlier sutras,
Ksheenvritteh Abhijaatasyamaneh Grheetrigrahangraahyeshu Tatastha Tadanjantaa Samapattih
Vritteh: Modifications of mind
Abhijaatasya: Born out of, born in consequence of
Iva: Like, similar to
Maneh: Mani, crystal
Grheetri: Purush, one who experiences
Grahan: Sense organs and antahkaran, the medium of experience
Graahyeshu: Objects of the senses and subtle subjects, that which is experienced
Tatastha: Located in that
Tadanjantaa: Take the form of that
Samapattih: Completion, conclusion, taking original form
The chitta born out of diminishing of the vrittis is like a crystal, which when put on grahitri, grahan or grahya, assumes their form, thus revealing their original/actual form.
When the ripples or disturbances called vrittis get diminished, the chitta becomes clear, just like a crystal through which one can see clearly. This chitta is able to distinguish between and reveal the actual swaroop of the purush, the sense organs and antahkaran as well as the objects of experience by assuming the form of that on which it is focused. A Yogi or Guru, is often compared to a highly polished mirror, in which one can see his/her own reflection, because of this crystal clear state of chitta, which is able to grant the experience of one’s actual form. If you don’t like what you see when you meet a Guru, then it’s your reality that you are seeing.