What mineral is this? Egg-sized piece. Transparent pink color with glassy luster. Shows conchoidal fracture. The hardness is 7.

The mineral we are talking about here is Quartz.

Explanation:

Structure of this material is vitreous in nature And color that you suggested. Here is pink which is true for quartz because it can occur in any color that is suggested size given is egg shaped.

The crystals of this material would be hexagonal in shape and have a fracture that is colloidal in nature. The main property of the material that tells us that is mineral is quartz is its hardness which is equal to 7.