They also have celestite, emery, feldspar, limestone, magnesite, marble, perlite, pumice, pyrites, clay, arable land and hydropower.
From the telegraph.co.uk
Celestite is the densest known marine biomineral, but it readily dissolves in seawater, thereby releasing strontium back into the seawater.
From the sciencedaily.com
Uniquely, the spiny skeletons and cyst shells of acantharians are composed of crystalline strontium sulphate, known as celestite, precipitated from seawater in the upper ocean.