Malachite is a copper carbonate mineral with the formula Cu2CO3(OH)2. Malachite was a mineral pigment in green paints from antiquity until about 1800. It is green, has concentric light and dark bands and rosettes, and is tumbled or polished.
You can find Malachite in Romania, Mexico, New South Wales, Zambia, the Democratic Republic of the Congo, Russia, the United States (Arizona), and the Middle East. Malachite is a powerful stone but one that needs special handling. The copper content of this stone makes it toxic. Avoid breathing its dust. Only use the polished form.
This stone amplifies both positive and negative energies. It grounds spiritual energies onto the planet, and some people believe Malachite will be one of this millennium’s most important healing stones. It is an essential protection stone because it quickly absorbs negative energies and pollutants, picking them up from the body and atmosphere. Therefore, cleaning this stone after its use is extremely important.
The preferred cleansing method for this stone is to place it on a quartz cluster in the sun. Do not use salt, as this will damage the surface. Malachite can absorb plutonium pollution and guards against radiation of all kinds. Therefore, it should be placed in the home of anyone who lives near a nuclear or natural radiation source.
This stone clears and activates the chakras and attends to spiritual guidance. Placing the stone on the third eye activates visualization and psychic advice. In addition, placing the stone on the heart brings balance and harmony and opens the heart to unconditional love.
Malachite is a stone of transformation that encourages risk-taking and change. It shows what is blocking your spiritual growth, draws out deep feelings and psychosomatic causes, breaks unwanted ties and outward patterns, and teaches responsibility for thoughts, actions, and feelings.
When placed on the solar plexus, this stone aids deep emotional healing by releasing negative experiences and old traumas and bringing suppressed feelings to the surface. The angel we associate with the stone is Archangel Rafael, whose name means He Who Heals.
Sources:
Wikipedia
The Crystal Bible, by Judy Hall