It was a small, 35-millimeter film canister filled with Lahaina beach sand that first got Gary Greenberg started 15 years ago on his exploration of the microscopic differences of sand around the world.

When Greenberg peered at it through his high-powered microscope, he discovered a spectacular array of colors and shapes resembling jewels.

“I was sort of surprised at what was there,” said Greenberg, a research affiliate at the University of Hawaii Institute for Astronomy on Maui. “It was so colorful and the shapes were amazing. Sands are amazing, biological fragments going somewhere and coming from somewhere. They’re snapshots in time. On Maui, sand is beautiful. It’s a wonderful mixture of volcanic-origin grains and coral reefs.”

Magnifying the sand 75 times, Greenberg observed a pink and white bit of a broken seashell, along with a Y-shaped glassy structure that was a sponge spicule, delicately coiled forams (relatives of tiny, single-celled amoebae that produce calcified shells) and a bit of brown sea urchin spine.

He began to examine sand from shorelines throughout Hawaii and other parts of the world, embarking on a journey into the amazing beauty and diversity of sand. He has thousands of vials sitting in a lab that people send to him, waiting to be examined.

Sand grains magnified about 100 to 300 times from beaches around the globe, and even moon dust collected by Apollo astronauts, are featured in Greenberg’s new book, “The Secrets of Sand: A Journey Into the Amazing Microscopic World of Sand” ($27, Voyageur Press), co-authored by Carol Kiely and Kate Clover.

The 128-page book features more than 100 images of sand from Maui to the shores of the island of Corsica in the Mediterranean Sea and the sandbar near Lava Falls at Grand Canyon National Park.

Greenberg’s goal was to show how different environments shape sand, and how the sand from a particular beach is a reflection of the ecology of that area, particularly in Hawaii.

“I wanted to show how different environments shape nature’s tiny sculptures,” he said.

Whether a grain of sand tumbled down from an eroding mountain or resulted from fragments of the hard tissues of marine organisms including shells, corals, sponges, sea urchins and forams, a high-powered microscope reveals varying textures, colors and shapes.

The cover of the book features star-shaped forams collected from a beach in Okinawa, Japan, magnified 75 times.

Greenberg sifts through a vial of sand beneath a microscope, using an acupuncture needle to find the best images to capture. It’s sort of like going on a treasure hunt, he said. The sand grains he photographs range, on average, between a tenth of a millimeter (about the diameter of a human hair) to half a millimeter.

“They are little jewels waiting to be discovered,” he said. “When we walk along the beach, we’re actually walking along millions of years of biological and geological history. We don’t realize it, but it’s actually a record of that entire ecology.”

As a matter of fact, no two grains of sand are alike, Greenberg said, an amazing concept, considering there are about 5,000 billion billion grains of sand on all the beaches of the world. Every single grain on every single beach is different, he said.

“Even more so than snowflakes,” he said. “Snowflakes are all symmetrical. With grains of sand, they’re entirely different — the colors, shapes, designs, they’re incredibly different. Even with a beach of all crystal sand, there are no two crystals that are exactly alike. Each is essentially unique.”

Greenberg, 71, was a photographer and filmmaker before obtaining a doctorate in developmental biology from University College London. While a graduate student in London, he worked on the 1977 production of “Superman: The Film.” To create visuals of the planet Krypton, he captured microscopic images of pancreatic cancer cells.

For him, art and science have always intersected. “When I’m an artist I combine science, and when I’m a scientist I combine art,” he said. “In Renaissance times they were both ways of exploring nature.”

With his background as a photographer, Greenberg in 1990 invented high-definition, three-dimensional light microscopes that make photographs of these sand grains possible in great detail. He holds 19 patents for them. His goal is to one day develop a microscope that can be launched into space.

At the Institute for Astronomy, where he founded the Microscopy & Microanalysis Lab, Greenberg continues to study moon sand collected during Apollo missions and micrometeorites (extraterrestrial particles that land on Earth).

Greenberg is already working on a third book, with the working title of “The Sand of Hawaii.”

“Hawaii has the most incredibly diverse and beautiful sand I’ve ever seen,” he said. “The variations and range of different sands in Hawaii is probably greater than any other place. There’s a whole range of volcanoes here, and they have different kinds of minerals. And then each island is covered with these reefs that are full of all kinds of biological material that leave behind tissues that become sand.”

When capturing microscopic photographs of sand grains, he likens himself to a landscape artist. “That’s how I see myself,” he said. “A landscape artist showing people places they’ve never been to.”

To learn more, visit sandgrains.com.