More pets are buried in U.S. backyards than any other place, but that is becoming illegal in more and more places. For those who want something unique, though, the sky's the limit.

From companies that will send your pet's remains to the heavens to those who will turn them into a gemstone for your favorite broach, there's a vast array of options.

Aquamation: This method is similar to cremation, but it's done with water-based technology that leaves pure ash reminiscent of powdery beach sand, said Jerry Shevick, CEO of Peaceful Pets Aquamation Inc. in New York. The process is called alkaline hydrolysis. It is legal for humans in seven states and legal for pets in every state. The nearly green, 20-minute process ranges from $75 to $350 depending on size.

LifeGem diamonds: LifeGem is a 13-year-old company in Elk Grove Village, Ill., that turns strands of hair or remains of a pet (or person) into a colorless, blue, red, yellow or green synthetic diamond that costs from $1,999 to $24,999.

Balloon lift: The Eternal Ascent Society in Newport Richey, Fla., will send your pet's ashes to the heavens, said Joanie West, who has owned the company for 16 years. She puts remains in a 5-foot-round balloon, adds helium and releases it at a tree- and wire-free location the family chooses. Families usually choose a service with music, gifts and remembrances. They can let the balloons go. Around 5 miles up at 40 degrees, the balloon fractures and the ashes are caught in high winds and scattered. Balloons start at $399. There are added costs for larger balloons, a videotape or special container.

Pet cemetery: Includes a plot of ground or mausoleum space. You can buy a headstone or plaque. Cemetery burial can cost several hundred to several thousand dollars depending on size, location, grave marker, type of casket or cremation, urn and other costs.

Cremation: Costs vary depending on location, pet size and extras. The Caring Pet Crematory in California charges $140 for a pet less than 20 pounds and $275 for a pet from 151 to 200 pounds. If the family wants to watch the cremation, it costs $50, but not every crematory allows witnesses, crematory operator Alex Gordon said.

Caring Pet normally scatters remains in the forest. For $125, the company will scatter remains off the coast of San Francisco by plane.