Clear calcite (optical calcite or icelandic spar) similar to clear quartz can be used to amplify one's intent. This stone is excellent for those in need of an "attitude adjustment" as using it during meditation can help one get to the root of what is causing negative feelings of anger, resentment, envy, or other heavy emotions that pair with a flair up of temper.
When used in meditation this stone can help being a deeper awareness and understanding of ones emotional state so that they may transmute it into something positive. Clear calcite can also help to give one clear vision.
Clear Calcite Affirmation:
"I see all aspects of myself and the world with ever-greater clarity, and I accept all that I see." - The Book of Stones by Robert Simmons & Naisha Ahsian