Misc: Varietal name applied to two different minerals?

Questions

"He who controls the past commands the ----------. He who commands the future conquers the past."- George Orwell?

"------------ are more dangerous foes of truth than lies."- Nietzsche?

"----------- have no souls, but they can love each other."- Henry Demarest Lloyd?

"---------- comes by being brave; fear comes by holding back."- Publilius Syrus?

"---------- is almost a contradiction in terms. It means a strong desire to live taking the form of a readiness to die."- G. K. Chesterton?