A small island can also be called an Atoll or an islet.
"Isle" is the word you seek.
Islet.
isle
It is an islet (small island).
isle
small island
small island
small island
Ellis island is a small island but because of sandy it is a wreck
Isle or Islet
key
An islet is a small island, especially one in a river or lake. It is often used to describe a tiny cluster of trees or vegetation within a body of water.
The word "island" is spelled with an "s" because it comes from the Old English word "Δ«egland," where the "s" was part of the original spelling. Over time, the "s" sound was dropped in pronunciation but retained in the spelling.