Dakshinavarti Shankh or Sri Lakshmi Shankh, is a sacred Hindu object otherwise known in English as a conch shell. 

These are Rare Conch Shells mostly Found in the Indian Ocean with the Reverse Turning Spiral which opens towards the Right Side

"In other words, when it is held with the spout (siphonal canal) pointed up, this conch's spiral twists rightwards (dakshinavarti) rather than very much more common form, which twists leftwards (vamavarti)"

Uses

This shankh brings Peace, Prosperity and Happiness wherever it is kept.  

It is Believed that whoever keeps this shell in their locker or safe, will never face a shortage of food, money or clothing in their life.  

Students can keep it to enlighten their mind and sharpen their memory.

Filling it up with purified, energized water and sprinkling on a person or space is said to reduce the malefic effect of planets, black magic etc.