CALCITES

All calcites increase and amplify energy.  All calcites protect, ground, and center.  They cleanse stored negative energies and are used to not only cleanse ourselves but to cleanse rooms or spaces of negative energies.  Ice calcite and Iceland Spar are included in this category.  They will also reduce stress, calm fears and worry, and help to maintain inner peace.
Each color also has its particular attributes:
Emerald brings stability and success and is perfect for one in business for him/herself.  It is considered a stone of manifestation, again perfect for the business person.
Blue is especially calming and perfect for easily frayed nerves.  The bedroom is the room for this stone, it is said to calm insomniacs and allow them to relax and rest.  It is also considered an excellent aid to communication and eases discourse of opposing views.
Citrine, Amber, and Honey calcites are said to enhance one's memory.  They are associated with both the solar plexus and sacral chakras and bring balance between the two.  Amber calcite crystals are sometimes quite large and make wonderful massage wands. 
Orange and Tangerine calcite is used to restore mental and emotional equilibrium to those who are fearful and depressed.  Orange calcite is associated with the sacral chakra.
Pink and Cobaltoan:  Pink Calcite is a heart crystal with strong forgiveness properties. Use it to release fear and grief that has trapped your love energy from a past incident. It is an excellent remedy to increase self-worth and self-love and has a soft, loving energy that will dissolve your resistance to deep emotional healing.