Smoky Quartz is helpful for those with cancer as it draws negative energies out of the body. Smoky Quartz is also known for its strong ability to absorb and ground negative energies out of the body, and into the earth to be transmuted. These properties make Smoky Quartz a great support crystal for those undergoing chemo and radiation therapies. 
As a healing stone, Smoky Quartz aids in the proper functioning of the adrenals, the kidneys and the pancreas. It has a relaxing effect, helping to block negativity, and aiding in meditation. It also helps develop ones latent abilities as a Channel, or Medium.
Smoky Quartz stimulates and purifies the base Chakra and stimulates the movement of Kundalini Energy by channeling the white light energy of the Crown Chakra into the First Chakra.
It is believed to help one come to terms with their own circumstances, becoming more acceptant of their own bodies and lives. It helps us to make our dreams into reality. It stimulates pride, self respect and self esteem. 
Smoky Quartz is especially useful for grounding and draining away negative energy.

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.

 

Ruby stone stimulates the heart chakra in a way like no other gemstone. It helps you to set your basic value system and decide what is acceptable in your world and what is not. This is the pure value system that is unadulterated by the heart aches and chest pains the world dishes out at times.

The protective abilities of the Ruby stone may be why it was so often used in the breast plates and shields of Kings and Knights of old. In our modern times, it makes an excellent stone to wear as a shielding stone. Simply carry or wear a stone so you can easily get to it and when you feel the need for protection, grasp the stone and visualize a bright red light shining out from it and surrounding your entire being.
You can also pre-program a ruby stone as a shield so it can send out protective energies to surround you at all times. This is an especially good way to help prevent psychic attacks.
The instances of life that are the most troublesome to us, often happen for a specific reason, a life lesson needing to be learned or to bring us back into alignment with our true selves and the needs and desires we are able to fill in the world. 
Ruby stones can help you see the lessons you need to learn before the turmoil hits in our lives. Of course each instance is different but occasionally we can keep from having to deal with these events.
It is believed by some cultures that if you own a ruby stone, you will never lose your wealth and is often used in work to ensure the stability of your income.
To help improve your ability to enter a Lucid Dream State, wear or carry a ruby stone during your attempts. It helps you to remain lucid while entering the dream state and increases your ability to control the dream without slipping into a normal sleep pattern.

 

Amethyst is purple Quartz, and is a meditative and calming stone. It works in the emotional, spiritual, and physical planes to provide calm, balance, patience, and peace. Amethyst is also beneficial when dealing with legal problems and money issues, which can lead to prosperity and abundance.
Emotionally, amethyst can help heal personal losses and grief. Amethyst has a gently sedative energy that promotes peacefulness, happiness, and contentment. It also brings emotional stability and inner strength, and can enhance flexibility and cooperation. Amethyst can help get rid of addictions (alcohol, drugs, smoking, etc.) and compulsive behaviors of all kinds.
In the psychic and spiritual realms, amethyst is an excellent all-purpose stone that can increase spirituality and enhance intuition and psychic powers of all kinds. It does this by making a clear connection between the earth plane and other planes and worlds. Amethyst is also excellent for meditation and lucid dreaming. It is known to open one's channels to telepathy, past life regression, clairaudience, clairvoyance, and communication with angels. Amethyst also protects against psychic attacks, especially during spiritual work, and protects one from thieves, and protects travelers.
Physically amethyst is said by spiritual healers and mystical lore to heal the withdrawal symptoms of any sort of addiction, help with headaches, insomnia, arthritis, diabetes, pain relief, circulatory system issues, endocrine system problems, chronic fatigue, fibromyalgia, immune system deficiencies,asthma, phobias, pregnancy and preventing miscarriage, menopause, PMS, and general healing.
Amethyst is associated with the third eye and crown chakras primarily, but can also open the heart chakra.