Complex sentence: Gendron discovered a jadeite sample with a composition suggesting it was formed 80 to 90 km underground, much more than the expected 20 km, around which jadeite is usually known to form.
Split into simpler sentences: Gendron discovered a jadeite sample with a composition suggesting it was formed 80 to 90 km underground. Much more than the expected 20 km, around which jadeite is usually known to form.