Among those watching the price of gold closely in coming months will be the Bureau of the Mint, which will offer two gold medallions for sale from July 15 to Jan. 31, 1982.

The Mint will offer two more American Arts Commemorative Series medallions beginning July 15 -- a one-ounce gold medal honoring Mark Twain and a half-ounce medal honoring another writer, Willa Cather. The price of the medallions will be based on the New York Commodity Exchange (Comex) settlement price for spot gold on the preceding business day, plus a premium to cover production and distribution costs.

Last year, when the Mint sold Marian Anderson and Grant Wood medallions, the price of gold was soaring and some medallions sold for more than $600 an ounce. The Treasury Department was able to put approximately $240 million into its general fund from medallion sales.

Recently gold prices have declined generally, with the closing price up New York at the end of business Friday at $418.25. The price is still substantially higher than the gold from Treasury stocks from which the medallions are made, which was acquired at $42 an ounce.

"The profits are substantial," said Francis Frere, assistant director of marketing for the Bureau of the Mint.

Legislation authorizing the striking of the medallions was passed by Congress to allow Americans to buy American gold.

Donna Pope, director-designate of the Mint, said this year's medallions will be packaged individually in presentation cases that will also contain a short biography of the artist. Customers can obtain each day's price by calling a toll-free number. The number for the continental United States is (800) 368-4410. From the Washington area, the number is 783-3800. s

The number will also provide information about how to order.

Buyers are limited to 25 medallions per transaction, with a maximum of five transactions allowed. Order forms and envelopes can be obtained at local post offices, which will also validate the order date, fixing the price. Payment must be by U.S. Postal Service money order, certified check or cashier's check.