Associated with deep spirituality and devotion, sapphire is considered to bring peace and contentment to one's soul, as well as trust in the fulfillment of his or her destiny.
Because it evokes the energy of loyalty, honesty, and devotion, the sapphire is often used in the design of engagement rings. 
The most important attribute of the sapphire was said to be the protection against sorcery- it was thought to banish evil spirits and send negative spells back to the sender. Sapphires were once used to guarded off poisonous creatures and kill snakes hiding nearby.
They also provided advanced warning against hidden dangers. As a tool for self improvement, sapphires are a wonderful way to keep your life in check. They are said to have a powerful and transformative gemstone energy that may work quickly and drastically. They will help you connect to the universe, that is, they can open your internal and spiritual self to the powers of the universe.
They are also thought to increase communication with, connection to, and awareness of spirit guides, or angels. They activate and manifest one’s life purpose and focus and karmic agreements for soul growth. Psychologically, the sapphire helps maintain inner peace and are good for one’s mental state. They calm nerves and promote mental clarity, helping with focus and concentration. They have also been used as remedies for mental and nervous disorders.

Garnet is known as the stone for a successful business. If your business is not as good as it should be, just put 3 or more garnets on your desk. It is believed that if a garnet is put under a pillow it will cure depression. Garnets can be used to make a person popular and have self-esteem when worn as jewelry. It helps protect one on trips. Garnets bring constancy to friendships. Garnets are also known for stimulating success in business.
Garnet comes in many colors, but now we will speak only about red Garnet. The Garnet is associated with the thyroid and spleen. It helps cleanse and purify both when held over the area. The Garnet is usually held in the hand or placed on top of the head when searching or meditating on past lives. Information that is beneficial and helpful will usually be released for the searcher.

Garnet is a stone of purity and truth as well as a symbol of love and compassion. The information released in a search may be painful, but it will always be what the searcher needs. The Garnet will help everyone's security level and spiritual awareness.

 

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.

In short, diamonds represent faithfulness, love, purity, innocence, and relationships filled with love. It removes certain types of deviations in the aura, which can be best imagined as sort of voids, and diamond fills them with the pure energy of love. It inspires creativity, ingenuity, inventivity, faith, endurance, and helps in manifesting abundance in all areas of life. Diamond is a symbol of the richness of the Self. As the hardest mineral of all, it is especially esteemed owing to its beauty, purity, and ability to reflect light in a special manner. Diamond brings purity, and clear positive resolution of all problems that bother us, especially after we have become willing to admit our wrong perceptions and approaches, or our unreal expectations. Diamonds work together with other crystals in accentuating their vibratory, healing qualities and can be used for example in crystal healing therapy.
The Hindu tradition relates diamonds to the planet Venus, while some other ancient peoples believed that they are connected to the planet Mars. The later is probably due to the warriors' custom of wearing diamond stones in battle for protection and strength. It was thought that diamonds make the warriors invincible and that they fortify their muscles. In favor of this thesis speaks the Greek word for diamond - adamas - which means invincible. 

The diamonds have been called kings of all crystals, stones of the mind and gemstones of the masters. This is no doubt, the most powerful crystal imaginable in the domain of metaphysics. It is able of reaching deep into us and opening much more spiritual doors than any other stone. Even more than that, diamond is able to bring abundance and fulfillment of the desires or undertaking you can only dare to imagine. If you dare to dream your own and true destiny, diamond is here to help you accomplish it. 

In meditation, as a stone of the intellect, it helps the mind to detach itself from the unwanted and unnecessary thoughts, bringing mental clarity to where it is most needed. Indeed, the picture of a perfect brilliant diamond was often used in the meditative practices of different spiritual traditions for thousands of years. 

Diamond activates the seventh crown chakra Sahasrara. It unites the body with the mind, and is able to help prevent cardiovascular diseases. It can stimulate the glands of the endocrine system, and help in cases such as leukemia and skeletal problems. It can enhance sight, and help balance the metabolism. It is believed to be able to heal capillary bleeding. Diamond gives an increased power to help resist addiction, especially if related to increased food intake, and cigarets. 

Due to its metaphysical features, there is no need to internally purify or do crystal charging of diamonds. So indeed, I hope you have realized what the meaning of diamonds is and how powerful they are in sense of their metaphysical, healing and spiritual properties. The price of the natural gemstones is high, but their benefits can also be substantial if you know how to properly use them in healing, meditation, and crystals programming.