Quartz

Lemon - Is believed to filter out distractions, aid concentration and open memory. Reduces anxiety, aids in bringing in money or assistance in times of need, and decreases negativity. Advocates recommend it be used with the third eye and crown chakras.

Rose Quartz - It restores trust and harmony in relationships, encouraging unconditional love. Purifies and opens the heart at all levels to promote love, self-love, friendship, deep inner healing and feelings of peace. It's Calming and reassuring, helps to comfort grief.

The Watermelon Quartz brings light, love, and rejuvenation to help keep ones heart and mind filled with joy, general happiness, brings out the more adventurous side, having increased daily energy, self-love and confidence. 

Bring on the love!
Due to its ability to balance, its also great for harmonizing and stabilizing one's environment . It is said to increase healing energy and is  effective for chronic fatigue, arthritis, bone injuries, depression, diabetes, fibromyalgia and gastro-intestinal troubles.
Clear Quartz - A meditation, that aids in enhancing mental clarity, aids in emotional stability. Great to be used during manifestation as it increases focus.
Helps clear the mind to see new truths and perspective.