The ancient greeks believed it was turned pink by the blood of the godess Aphrodite and her lover Adonis. Gifts made of rose quartz were popular amongst courting roman youths.
In modern new age spirituality, rose quartz heals the heart and heart chakra. It is used to bring love and peace while also strengthening one's empathy and self-acceptance. Rose quartz reduces tension and grief while enhancing sobriety, especially when used with amethyst.
Rose quartz is also said to promote one's receptivity to beauty and this rings most true for me. My personal reaction to stones stems from my sensitivity to color. The semi-translucent, gentle pink is somewhat of a "palette cleanser" for my eyes. In my jewelry, I often like to pair rose quartz with iridescent glass.