The Cremators (1972)

Dr. Iane Thorne is an entomologist working on research as he lives by himself in a remote location. While recording field observations one day, he notes some unusual blue and green marbled mineral nodules in a shallow pool. He picks them up, checks them in the lab, and then decides to mail to a colleague for his opinion on their composition. The package never makes it because the postal carrier transporting it in his car encounters a huge glowing ball of light and matter that completely incinerates him. The same thing happens to another man; just a smudge of ashes is left. Jeanne, the niece of Iane's friend and a high school sweetheart, comes to visit. She is attracted to the nodules and he gives her a pair of them. It is only in a nick of time that Iane determines that the nodules are alien "children" who were separated in a fiery impact millennia ago that are being reclaimed by the mother mass as they are discovered.