A single quartz crystal carried on ones body will assist in maintaining balance, energy and protection.
All of the psychic abilities can be stimulated and amplified using quartz. It has the property of retaining calmness and clarity in every situation, decreasing negative energy that could inhibit emotional stability. It aids in perseverance and patience.
Quartz responds extremely well to the heart chakra and the third-eye chakra. In the heart chakra, it helps to clear emotional disturbances, enhances the states of self-help and self-love. In the third-eye chakra, it enables one to focus more clearly with the mind to empty the mind. It also promotes reflection, magnification of images and thoughts. Quartz, when used for the crown chakra, produces a spiraling effect that remove the Kundalini for access to the spiritual realm. If one has not overcome personal will and open the crown chakra it can produce disruptions in the emotional, physical and spiritual centers. Quartz can direct ones materialistic energies towards the spiritual realm. Quartz cancels harmful effects of radiation and radioactivity.

Rose quartz is pink quartz that is often called the "Love Stone." It is a stone of unconditional love that opens the heart chakra to all forms of love: self-love, family love, platonic love, and romantic love. The high energy of quartz gives rose quartz the property of enhancing love in virtually any situation. In turn, this lowers stress. All in all it is a very soothing and happy stone.
Emotionally rose quartz brings gentleness, forgiveness, compassion, kindness and tolerance. It raises one's self-esteem and sense of self-worth. It helps balance emotions and heal emotional wounds and traumas, even grief, bringing peace and calm. Rose quartz removes fears, resentments and anger. It can also heal and release childhood traumas, neglect, and lack of love, in part by enhancing inner awareness. It can help with reconciliation with family and others. Overwhelming or unreasonable guilt is eased by rose quartz.
In the psychic and spiritual realms, rose quartz is often used to attract love, and for love spells. It is also used to ease the process of transition in dying. Rose quartz can be helpful for dream recall and dream work.
Physically rose quartz is used in crystal healing to benefit the heart, the circulatory system, fertility, headaches, kidney disease, migraines, sexual dysfunction, sinus problems, throat problems, depression, addictions, ear aches, slowing signs of ageing, reducing wrinkles, spleen problems, fibromyalgia, and reaching one's ideal weight / weight loss. Rose quartz is also helpful and protective during pregnancy and with childbirth. It is also sometimes said that rose quartz is helpful for supporting brain functions and increasing intellect.

In addition to the generic healing properties of Quartz, the Green Quartz or Prasiolite variety, opens and stabilises the heart chakra.  It promotes an intuitive capability which is coupled with love.  Prasiolite is a stone of tranformative energies.  It transmutes negative energy to positive without releasing it to the atmosphere.
Prasiolite inspires creativity, attracting success, prosperity and abundance.
Prasiolite aids the endocrine glands, helping to keep the body balanced.

The most important property of citrine is that it dissipates negative energies of all kinds and does not absorb any negative energy from its surroundings, and thus never needs clearing/cleansing. 
Citrine can be used to clear unwanted energies from the environment. Family issues caused by negative energies can also be resolved and cleared with citrine. Since citrine eliminates negative energies, it helps generate stability in all areas, and is good for general protection.

In the mental area, citrine enhances mental clarity, confidence, and will power. It also increases creativity and promotes honesty.

Emotionally, citrine relieves depression, self-doubt, anger, and irrational mood swings. Citrine is a stone that brings happiness and cheer to one who carries or wears it. Citrine also reduces self-destructive tendencies. Citrine helps eliminate fears caused by others' ideas and suggestions. It can help one overcome emotional traumas and grief. Sensuality and sexuality can also be heightened by citrine.

In the psychic and spiritual realms, citrine is good for general psychic awareness and spiritual development. Citrine clears the aura of negative energies and influences. It is also very useful for meditation. Citrine is a stone of protection, removing or deflecting negative energies of all kinds. It is also excellent for dream recall and dream work.

Physically, in crystal healing and folklore, citrine is said to be beneficial for the digestion, stomach, eliminating nightmares and other sleep disturbances, thyroid, general health, heart, kidney, liver, muscles, strength, endocrine system, circulatory system, tissue regeneration, urinary system, immune system, diabetes, fibromyalgia. Citrine is also reputed to be good for removing toxins, and overcoming addictions.

Prehnite is considered a stone of unconditional love and the crystal to heal the healer.  It enhances precognition and inner knowing.  Enables you always to be prepared.  Prehnite calms the environment and brings peace and protection.  It teaches how to be in harmony with nature and the elemental forces.  Helpful for “decluttering” – letting go of possessions you no longer need, aiding those who hoard possessions, or love, because of an inner lack.  Prehnite alleviates nightmares, phobias and deep fears, uncovering and healing the dis-ease that creates them.  It is a stone for dreaming and remembering.  Beneficial for hyperactive children and the causes that underlie the condition.
Prehnite heals the kidneys and bladder, thymus gland, shoulders, chest and lungs.  It treats gout and blood disorders.  Prehnite repairs the connective tissue in the body and can stabilise malignancy.