KYANITE
Also called Disthene, the name kyanite is derived from Greek word kyanos which means 'blue'. Prominently, kyanite is found in shades of blues & greens. Being a rare gem and also quite brittle, Kyanite is best used mainly for earrings, brooches & pendants, rather than rings.
This shiny, translucent gemstone is known for its colour zones & variation in hardness. The associated zodiac signs are Aries, Taurus & Libra. Brittle in appearance and easy to damage kyanite is challenging to cut.
Kyanite belongs to the class of silicates.
Derived from Aluminum silicate, Kyanite is polymorph with mineral andalusite &
sillimanite i.e. they have similar chemistry but different crystal structure.
Mineral kyanite has typical blue colour & wide variation in hardness, which can
be called its unique characteristics. It's hardness may vary from 4-7.5 in the
same specimen crystal. Usually, Kyanite found in rocks that are formed in high
pressure conditions that is to say metamorphic rocks.
Although it has characteristic blue colour, Kyanite may be green, yellow, white.
These are the properties it is said to possess:

It is good for the throat & is effective in clearing sinus congestion.
Kyanite has a positive effect on dreams, visualization, psychic activities, foresightedness & meditation.
It stimulates flow of energy, concentration power, communication abilities & metal exercises.
Associated with serenity, loyalty, honesty, it helps in dispelling anger, frustration & temper.
Kyanite has remarkable effect on dreams, memory, removing mental misconceptions. It promotes mental clarity & spiritual balance
It encourages new thoughts & ideas , helps recollection, telepathy, etc.
It is a widely recommended gemstone for mental peace & energy, usually used on throat & third eye chakras.
It is a well-accepted tool for meditation & relaxation.