Thanks for the research. I challenge you to find a reference and to tell me what it says.
density of the quartz =2.65 g/cm3 density of the granite= between 2,63 and 2,75 g /cm3 (depending on the sort of granite) density = specific weight
Weight Of Quartz Countertop
quartz is is definitely your best bet, how do i know i install granite and quartz, and to tell you the truth i am pleased when i see that were carrying quartz instead of granite, because its definitely lighter