Meerschaum (German for "sea foam") is a mineral deposit, technically called hydrous magnesium silicate. It's very light in weight, porous and resistant to heat. It has a number of other properties that make it ideal for use as a tobacco pipe- it's neutral in flavor, is easy to carve into intricate shapes and it takes on a wonderful patina as it's smoked. The main drawback of these white to ivory to pinkish pipes is fragility. They won't withstand hard impact and shouldn't be smoked in frigid temperatures as they can crack. But for unique appearance and a cool, dry smoke, it's hard to beat a meerschaum.