Trying my hand at Riddling.

For centuries my beating heart has lain silent. Parents came flocking to me in droves, desperate for a sanctuary in which to nurture their children, and I looked greedily upon them, waiting patiently to snatch up their grandchildren and offer them up to the masses. These brilliant little sparks of mine, they once shined so bright, but now, they lay dormant, stricken by the sands of time, beyond even the help of the brightest light. I have been conquered, converted, and now I lie silent, my eyes dry, where tears of joy sprung once, now sits only sand. Who or what am I?