Summa Metals, Corp.
================================================================================
1588 Lancer Drive - Lake Havasu City, Arizona 86403
Tel-Fax (520) 630-5513 - (714) 348-9749


March 1, 1999

Mr. Amyn Dahya
Casmyn Corp.
1500 North Georgia St.
Suite 1800
Vancouver, British Colombia V6G2Z6

                          RE: Extension of $100,000.00

Dear Amyn:

Again for a variety  of  reasons,  we are  needing to extend the due date on the
above referenced note. While I understand that your real interest is the shares,
we continue to need additional time to pay this note. In addition,  I would like
to discuss the  possibility  of  converting  this debt to stock if you are still
interested.

The note has  therefore  been  modified to extend the payment date until Monday,
September  5th,  1999.  This note shall  continue  to bear  interest  during the
extended period as originally set forth.

The company greatly  appreciates your continued  patients in this matter. I will
contact you or your representative after we are effective with the IPO.

Sincerely,
THE SUMMA METALS CORPORATION

- ----------------------------------
Michael M. Chaffee
President                       Acknowledged
                                            --------------------------------
                                            Amyn Dahya


                   ARIZONA - NEVADA - CALIFORNIA - CHIHUAHUA