http://i.imgur.com/9gY00mh.png

http://www.uesp.net/wiki/Skyrim:Bloodstone_Chalice#Bloodstone_Chalice

so what does it do how do i get access to it again ?

I believe it gives minor boosts to a vampire. You do the quest on the Volkihar side.

yeah i completed it but what are the boost ?

IIRC, I think it increases the Vampire Drain spell by a bit.

Activating the chalice grants the effect, Blood of the Ancients, which makes the Vampiric Drain spell absorb Stamina, Magicka, and Health for one day. The duration can be lengthened up to a maximum of 11 days by completing Ancient Power (a radiant quest). This quest can be completed up to 5 times.

Effects:

Your Vampiric Drain spell absorbs Magicka and Stamina from your victims for x days

Note: the possible values for x are 1, 3, 5, 7, and 11 depending on how many Ancient Power quests you have completed

I think basically, the main difference between this boost and the regular vampire drain spell is that it also absorbs Magicka and Stamina, not only Health, from victims.