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.
 

Mother of Pearl has tremendous ability to calm and lessen the fears of those who wear it, it is especially helpful for anyone whose life is intense and stressful.
It is said to attract prosperity.
It is used in mystical work 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.

 

Black Onyx is a good stone to have around during times of mental or physical stress or bereavement, as it provides strength and support during difficult circumstances.
Black Onyx is a soothing stone said to help alleviate fears and worries and to help you to feel comfortable within yourself and in your surroundings. It is also believed to promote stamina and vigour and to encourage the making of wise decisions.
Black Onyx is said to promote self-control helping the wearer to keep excessive emotions and passions under control.
Onyx is an excellent mineral for initiating modes of centering and aligning the total person with the higher power. It can be used to get rid of grief, enhance self-control, stimulate wise decision-making, and encourage happiness and good fortune. It is used to cleanse ones intuition receivers, in that one feels whole, while continuing to be aware of opportunities around us for use with intuition guidance. Onyx can facilitate one to see the duality of ones nature and to energize the Yin-Yang into the whole. It aids in foreseeing of what lies beyond and provides for activation of ones memory with respect to ones roots and reality. It aids in one to become the master of their future. It has been used in the breastplate of the high priest. Black onyx and red onyx are associated with the base (root, first) chakra. White onyx is associated with linking the base and crown chakras to have balanced energy throughout the chakra system.