Great Beauty Spreads A Firestorm

Great beauty spreads a firestorm
across a thousand ardent wills
which, so dispersed, is lightly borne
but, gathered into one, may kill.
As weight on many points can rest
that can't be borne by one alone:
so heat that's bearable if spread,
when pent in kilns, will crumble stone.
(I know first-hand how mortar's made,
by slurrying the roasted dust.)
Her excellence has fired my mind
until it cannot bear more love;
my heart, once hard, has been calcined
to dust that weeping will dissolve: