United States

A variety of organic sand grains including red foraminifera (forams), a clear triangular sponge spicule in the center, short rods of calcareous algae, and bits and pieces of coral...

Only 9 miles long and 2 miles wide, St. John boasts of lush emerald mountains, hills and valleys without many flat areas, and soft white coral sands on numerous near-deserted tranquil beaches...

Although St. John is a volcanic island and part of a submarine mountain range extending from Cuba to Trinidad, sand on recreational beaches is primarily biogenic. This beach sand...

A sand mixture of calcified algae, coral fragments, bits of mollusk shells, and pale and red forams reflects the diversity of adjacent sea life surrounding this island. Most of these sand grains...

This mixture of white and tan sand grains includes grooved fragments of mollusks and fragments of calcareous algae and smoothly worn forams. The red grains are fragments of the foraminifera...

This large mixture of sand grains is essentially of biogenic origin representing bleached coralline algae and fragments of coral with the exception of a larger dark grain of volcanic origin...

Among the larger sand grains are light tan and brown mollusk shell fragments. The black grain with thin vertical white stripes just below center is also a mollusk shell fragment while the smaller...