Ooid Is A Type Of Sand That Grows
Sand is a term for worn down fragments of any material. Gravel has a diameter bigger than 2mm, and silt is smaller than 0.063mm; anything in between is sand. Ooid, however, is the only sand that accretes rather than erodes. It accumulates calcium in the ocean until it is a grain the size of a pin tip.
Check Out This Month's Most Popular Topic
from Deep Look
Key Facts In This Video
Sand can be any material that has been worn down until it's reduced to tiny fragments. (0:17)
Silt is just sand that is finer than 0.063mm (0.0025in) in diameter. (0:27)
Ooid is the only sand that accretes rather than erodes. (1:40)