<PAGE>

                                                                     EXHIBIT 3.1

       Set out below is a composite of the Certificate of Incorporation of the
Company as originally filed on November 13, 1992 and as amended on March 9,
1993, December 14, 1993, August 10, 1995, June 24, 1998 and March 1, 1999. The
certificate of incorporation of the Company has not been restated on the records
of the Delaware Secretary of State.

                          CERTIFICATE OF INCORPORATION
                                       OF
                         AMERICAN STONE INDUSTRIES, INC.

       FIRST. The name of the Corporation is AMERICAN STONE INDUSTRIES, INC.

       SECOND. Its registered office in the State of Delaware is to be located
at Corporation Trust Center, 1209 Orange Street, in the City of Wilmington,
County of NewCastle. The registered agent in charge thereof is The Corporation
Trust Company at Corporation Trust Center, 1209 Orange Street, Wilmington,
Delaware 19801.

       THIRD. The nature of the business and, the objects and purposes proposed
to be transacted, promoted and carried on, are to do any or all of the things
herein mentioned, as fully and to the same extent as natural persons might or
could do, and in any part of the world. viz:

       The purpose of the Corporation is to engage in any lawful act or activity
for which corporations may be organized under the General corporation Law of
Delaware.

       FOURTH. The Corporation shall be authorized to issue the following
shares:

<TABLE>
<CAPTION>
Class                           Number of Shares                       Par Value
------                          ----------------                       ---------
<S>                             <C>                                    <C>
Common                             20,000,000                            $.001
</TABLE>

       FIFTH. The name and mailing address of the incorporator is as follows:

<TABLE>
<CAPTION>
     Name:                                            Address:
---------------                        ---------------------------------------
<S>                                    <C>
Kimberly Andras                        201 N. Walnut St., Wilmington, DE 19801
</TABLE>

       SIXTH. The powers of the incorporator are to terminate upon filing of the
Certificate of Incorporation, and the name and mailing address of the person who
is to serve as the first director until the first annual meeting of stockholders
or until his successor is elected and qualified is as follows: Michael S.
Wexler, 130 Slater Street, Ottawa, Canada K1P 6E2

       SEVENTH. The Directors shall have power to make and to alter or amend the
By-Laws; and to fix the amount to be reserved as working capital.

                                  Exhibit 3.1
                                  Page 1 of 2

<PAGE>

       The By-Laws shall determine whether and to what extent the accounts and
books of this Corporation, or any of them shall be open to the inspection of the
stockholders; and no stockholder shall have any right of inspecting any account,
or book or document of this Corporation, except as conferred by the law or the
By-Laws, or by resolution of the stockholders.

       It is the intention that the objects, purposes and powers specified in
the Third paragraph hereof shall, except where otherwise specified in said
paragraph, be nowise limited or restricted by reference or to inference from the
terms of any other clause or paragraph in this Certificate of Incorporation, but
that the objects, purposes and powers specified in the Third paragraph and in
each of the clauses or paragraphs of this charter shall be regarded as
independent objects, purposes and powers.

       EIGHTH. Directors of the corporation shall not be liable to either the
corporation or its stockholders for monetary damages for a breach of fiduciary
duties unless the breach involves: (1) a director's duty of loyalty to the
Corporation or its stockholders; (2) acts or omissions not in good faith or
which involve intentional misconduct or a knowing violation of law; (3)
liability for unlawful payments of dividends or unlawful stock purchases or
redemption by the Corporation; or (4) a transaction from which the director
derived an improper personal benefit.

       NINTH: The Corporation elects not to be governed by Section 203 of the
General Corporation Law of Delaware.

       TENTH. The Corporation shall indemnify all persons whom it may indemnify
to the fullest extent allowed by the General Corporation Law of Delaware.

                                  Exhibit 3.1
                                  Page 2 of 2