It's pure. It's natural. It's good for your skin.

These claims and more have catapulted mineral makeup from a late-night infomercial buzzword to a full-fledged cosmetic phenom.

Want proof? Peruse the makeup aisle of your local drugstore or cosmetics counter. Revlon, Neutrogena, L'Oreal, Cover Girl and Physician's Formula have mineral lines. So do New York Color and Wet N Wild. Maybelline New York jumped on the mineral bandwagon in January. M.A.C. will make its mineral debut this year. And mineral makeup is now Avon's calling, as well.

Mineral-based cosmetic launches in the United States increased from 132 in 2005 to 451 in 2007, according to Datamonitor's Productscan Online.

So, what's the difference between mineral makeup and the other kinds?

Mineral foundation, powder, eye shadow and blush are touted as being better for your skin than traditional makeup because they're made from crushed rocks. The products are chemical and fragrance-free, so they're supposed to be less irritating to the skin. And titanium dioxide and zinc oxide, the base ingredients in many lines, work as a natural sunblock.

The application of mineral makeup is also different. A wide fluffy brush, called a kabuki brush, is used to buff the finely ground powders onto the skin. Done right, a little goes a long way, and users swear it feels as though they're not wearing makeup at all.

Consumers are definitely buying into the all-natural vogue: They purchased $149 million worth of mineral-based cosmetics last year from mass-market retailers such as Wal-Mart and Target alone. That's more than double the $69 million sold by such retailers in 2006, according to trend-tracker

Mineral makeup is no more expensive than traditional makeup. You can pay as little as $10 for a drugstore label such as Maybelline's Mineral Power foundation or as much as $50 for specialty brand Colorscience's Pressed Mineral Pigment.

Mineral makeup actually has been around for decades. The term was coined by entrepreneur Diane Ranger, who pioneered the formula for Bare Escentuals and launched the line in the 1970s. She sold the company in 1990 and founded the Colorscience mineral makeup brand, which is sold at high-end resorts and spas, makeup studios and doctors' offices.

"Mineral makeup is an overnight sensation 30 years in the making," says Ranger, who lives in California. "More women are seeing treatments and precautions as self-preservation rather than self-indulgence. They realize they have healthy options that offer them beauty."

Bare Escentuals has long been the trailblazer in the mineral makeup market. If you've ever tuned into the brand's late-night infomercial, most likely you've seen spokesperson and CEO Leslie Blodgett boasting that the line's popular powder is so pure you can sleep in it. The company recently introduced mineral acne fighters and facial cleansers.

Still, not everyone is buying into mineral mania. Paula Begoun, the author of "Don't Go to the Cosmetics Counter Without Me" (Beginning Press, $29.95), says manufacturers' claims that the makeup is made primarily from crushed rock is misleading.

For more than two decades, Begoun has researched and written about virtually every cosmetic product on the market, and she published the findings in two best-selling books. She says in her reviews that while the products claim not to contain fragrance, oil, binders, preservatives or other problematic ingredients, "that turns out not to be the case; bismuth oxychloride is a major ingredient in all the powder formulations, and it can cause skin irritation, while the other minerals can be drying."

Bismuth oxychloride, a byproduct of lead refinement, isn't a pure mineral. It's used to lend an opalescent luster.

"No one is getting it out of nature," Begoun writes. "The notion that there's something special or rare about mineral makeup is misleading. Only the cosmetics industry can take something ordinary and make it sound like a miracle."

Cloe Cabrera is a staff writer for the Tampa Tribune.