Malachite
Malachite is a stone of transformation and helps with change and spiritual evolution. It can clear and activate all chakras, as well as balance them. Malachite is a stone that bridges the energy of the heart and root chakras. It is particularly useful for balancing and clearing the heart chakra. As such, it helps balance pure love, romance, and one's own well-being. Malachite is a stone of good fortune and prosperity/abundance, too. Malachite is also a very protective stone, being especially helpful for general protection, protection from evil, protection during pregnancy and childbirth, and protection for children. It is also an excellent protection stone during flying and other travel. Using this stone, one can counteract self-destructive romantic tendencies and help encourage true, pure love. Malachite is also good for enhancing emotional stability and balance in general. It can decrease one's tendency to radiation illness, asthma, arthritis, and tumors.
Marble, Picasso (aka Picasso Stone, Picasso Jasper)
Picasso Marble (or Picasso Stone) is sometimes called Picasso Jasper. It has strong metaphysical qualities of grounding and calming. It also promotes weight loss and assists in the development of creativity, as well as engendering strength and self-discipline.
Mariposite
Mariposite is said to be a stone that reduces stress and helps us be calm and balanced. It is a stone said to help us adapt to change and be more flexible as well, from a calmer spiritual space in the face of change. This calm and balance from reduced stress also helps reduce fear, which in turn breeds more calm and balance. Mariposite is also said to help cope with energy overload, and avoid or eliminate exhaustion. It is also a stone of creative self-expression.
Mica
Mica is a group of minerals, also called Isenglass and Glimmer. All share common properties as well as each type having its own properties. Mica has reflective qualities to recognize flaws and see them with love. It is used to improve visions and clarity in mysticism. It is said to help eliminate negative personality traits by helping one recognize them. Mica is said to enhance flexibility in all realms and also assist growth in those areas. It is used to diminish anger, hostility, and nervous energy. Mica aligns energy of the body and releases blockages of energy within the body. Physically, mica is used in crystal healing and folklore to reduce hunger when fasting, insomnia, mononucleosis symptoms, dehydration. It is also said to provide energy and purpose. Mica comes in many colors and is associated with the chakra of similar color. Some types of Mica are Lepidolite, Muscovite, Fuschite, Phlogopite, Biotite, and there are others.
Moki Marbles (Moqui Marbles)
Moki marbles have long been used as a shamanic stone. It brings a knowledge and deepening of ancient ways. Moki marbles often have a slight magnetic charge, and they stimulate chi. They may be used to contact your animal spirits, totems, and guides, and to aid in shapeshifting. They help a great deal with grounding and centering. Physically they are beneficial for the veins, arteries, muscles and immune system. They have a protective quality and are useful for protection against psychic attacks and other unbalancing forces.
Moldavite
Moldavite is a tektite and is the only "extraterrestrial" gemstone, which is found only in the Moldau Valley in Czechoslovakia. Lately there have been other green tektites or imitations that are called "moldavite," but only the Czech moldavite is the "real thing." It is associated with the heart and third eye (brow) chakras, as well as the crown chakra. Moldavite is also associated with the Star card of the Tarot. It strengthens and enhances inner journeys, channeling, cosmic consciousness, crystal consciousness, expansion, contact with interdimensional or extraterrestrial forces. It is a powerful stone, and its energies can at first be intimidating for those that are not aware of its energy, and tends to bring issues to the surface to be transformed, thus making it called "stone of transformation." When wearing moldavite, it is best to be mentally prepared and be properly grounded. Moldavite diminishes contracting or withdrawing energies. Moldavite in any form increases the depth and clarity of inner journeys. Moldavite has been said to raise the vibrational level of both the human race and the Earth. Physically, moldavite works excellently with other crystals and stones to raise the vibrational level of all healing, and also heals hair loss, fertility issues, and promoting new cell growth.
Molybdenum
Molybdenum is a mineral that brings balance and continuity to life. It can help engender reliability and constance in one's environment and self, giving equilibrium in all areas of life. Molybdenum is also a super stress reliever. It can also be useful in retaining possessions and making progress. Molybdenum enhances communication between conscious and inner selves, as well as filling in holes or voids in the aura. It balances the chakras, as well as the physical body and the mind. Molybdenum is helpful for all types of healing because it energetically balances the body toward health.
Moonstone
Moonstone is said in crystal healing to help calm responses and avoid overreaction; enhances feminine energies, sensitivity, intuition, and psychic abilities. It is also said to bring strong energies of abundance to one's life. Moonstone is a stone of protection, especially during childbirth, pregnancy, and travel at sea. It is a stone of calm and relief from emotional stress. It is also associated with love of all kinds. Physically it aids the pituitary gland and digestive system, obesity, water retention, hormonal problems, menstrual problems. Moonstone is also used as a stand in for pearl, when pearl is not available. Moonstone is associated with the crown and third eye chakras, and sometimes with the heart chakra.
Moonstone, Rainbow
Rainbow moonstone has a gentle, calming energy. It helps to strengthen intuition and psychic perception, and enhances creativity, compassion, endurance and inner confidence. It is a stone that brings balance and harmony. The Rainbow effect brings in a spectrum of light, and can help with clearing and bringing in uplifting energies. It has been said to have the power to grant wishes. Rainbow Moonstone is primarily related to the Crown Chakra.
Morganite
Morganite is known both as an angel stone and a heart stone. It can bring love to one's live or rekindle old love. As an angel stone, it is known to help with communicating with angels. Morganite also brings compassion, empathy, self-control, and patience. It can also balance emotions and ease the pain of separation. It has been said to be one of the highest frequency stones available. Physically, morganite is used for healing emphysema, tuberculosis, heart disease, breathing problems, and throat problems. Morganite is associated primarily with the heart chakra, and can open, balance and clear this chakra.
Mother of Pearl 
Mother of Pearl gets its name from the fact that it is the iridescent lining of shell, where pearls can grow. Mother of Pearl has both traditional and New Age metaphysical and healing lore. It is said to attract prosperity. It is used in mystical work and lore to heighten intuition, psychic sensitivity, and imagination. It is purported to protect from negative influence, and transmute negative energy. It is said to be highly protective and a particularly potent stone of protection for children. A traditional lore use of Mother of Pearl is to purify environments. Mother of Pearl is also used in metaphysics to access primordial and racial memories. Crystal healing and folklore say that Mother of Pearl is helpful for high blood pressure, dizziness, improving vision, cataracts, and wound healing.
Muscovite
Muscovite is a type of mica that comes in pinks, browns, clear and yellows. It has both the properties of mica as well as its own particular ones. It is a stone of angelic contact, and can bring awareness of the higher self. Mystically it is used in scrying and can contact the highest spiritual planes, as well as assist with astral travel. Muscovite is also good for lessening insecurities, self-doubt, and brings self-confidence and optimism. It is considered good for problem-solving, self-reflection, and dealing with major life changes. Physically, muscovite is used in crystal healing to balance the pancreas, control blood sugar, heal dehydration, kidneys, hunger pangs while fasting for medical or spiritual purposes, insomnia, allergies, disease-related conditions.