U.S. SHOWS AND EVENTS March 3-9 ? United Jewelry Show, Providence, R.I. (401) 331-7630, fax (401) 521-7488. 5-7 ? 53rd Annual Gem and Mineral Show, Hayward, Calif. (510) 581-7123. 13-14 ? Wisconsin-Illinois Jewelry Expo, Madison, Wis. (608) 257-3541, fax (608) 257-8755. 20-23 ? Columbus Gift Show, Columbus, Ohio. (770) 952-6444, fax (770) 956-9644. 27-28 ? Greater Great Lakes Jewelry Exposition, Livonia, Mich. (800) 366-3699 or (517) 372-5656, fax (517) 372-1303. 27-28 ? EJTA Charlotte Jewelers Market, Charlotte, N.C. (800) 595-3582 or (704) 504-1300, fax (704) 504-1333. 27-29 ? GlobalShop 1999, Chicago, Ill. (800) 646-0091. April 7-11 ? American Gem Society Conclave, New Orleans, La. (702) 255-6500, fax (702) 255-7420. 10-13 ? International Jewelry Fair/General Merchandise Show, New Orleans, La. (630) 241-9865, fax (630) 241-9870. 15-20 ? High Point Decorative Ac