Rock salt is unrefined and gray in color.
Kosher salt is coarse, refined rock salt with lime.
Sea salt is evaporated or distilled from seawater collected in salt pans.
Sel gris is unrefined sea salt, named for its gray color.
Table salt is ground and refined rock salt. In the 1920s, manufacturers added iodine to it to prevent thyroid deficiency problems.
Collector Janet Cam is using salt from:
* France: Fleur de sel de Guerande, Cam's favorite salt; fragrant and glittery, used by bakers on loaves, she likes it for finishing. "I love the crunch." 4.5 ounces, $6.50 at La Cuisine, 323 Cameron St., Alexandria; 703-836-4435; www.lacuisineus.com.
Sel gris, damp, grainy. Good all-rounder for cooking. 2.25 pounds, $6 at La Cuisine.
* England: Maldon sea salt; flaky crystals, mild, briny. "More multi-layered in taste. Only use it for finishing." 8.5 ounces, $7 at La Cuisine.
Anglesey: Like Maldon but damper. "Look at the glitter!" 5.6 ounces, $10.99 from Kalustyan's, 800-352-3451, www.kalustyans.com.
* Bali: "Big crystals, subtle flavor, a crunch without salinity -- a good cooking salt." 8.5 ounces, $8 from Williams-Sonoma, 877-812-6235, www.Williams-sonoma.com.
* Portugal: Crystal flakes, "very intense." Good for finishing. 17.5 ounces for $6.99, from Igourmet, 877-446-8763, www.igourmet.com.
* Panama: Very salty, floury texture and finish for cooking.
* China: Black pepper salt. A cooking salt, good in a steak rub. Kam Sam Supermarket, 300 N. Washington St., Rockville, 301-315-9558; and other Chinese markets.
* Italy: Sale alle erbe. Small herb-infused grains good for crusting a roasted fish. 10.5 ounces, $7.50 at La Cuisine.
* Korean: Powerful with a strong sulfuric flavor for cooking. From Indian markets.
* Japan: Lake salt. Small grains for cooking.
* Australia: Lake salt with less sharp flavor and larger, drier grain. For cooking and rubs. Australian Murray River Salt Flakes, 4 ounces, $9.50 from Salt Traders, 800-641-7258, www.salttraders.com.
* Greece: "Very, very salty. The most different in taste, very mineral-y." Fine-grained cooking salt. 8.82 ounces, $1.25 at Mediterranean Bakery, 352 S. Pickett St., Alexandria, 703-751-0030.
* Himalayas: Sel Rose. Dawn-pink. Subtle, crunchy texture for finishing. 8.8 ounces, $9.99 at Whole Foods Markets.
* Hawaii: Red sea salt. Deep reddish orange from iron oxide. Rustic flavor. Use as a colorful bed for oysters. Red Alaea Sea Salt, 4 ounces, $7 from Salt Traders, 800-641-7258, www.salttraders.com.
-- Julia Watson