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                              RESCISSION AGREEMENT

         THIS  RESCISSION  AGREEMENT  (the  "Rescission  Agreement") is made and
entered  into  this  ______  day of  April  2004,  by and  between  Cementitious
Materials,  Inc., formerly known as American Thorium, Inc., a Nevada corporation
(hereinafter  "ATI");   Cementitious  Material  Technologies,   Inc.,  a  Nevada
corporation   (hereinafter   "CMTI");   and  the  former  shareholders  of  CMTI
(hereinafter  "Shareholders")  as described in Schedule "A" attached hereto and,
by this reference, made a part hereof.

         WHEREAS,  the parties hereto previously  entered into and executed that
certain  Share  Exchange  Agreement  dated  the 5th day of  November  2003  (the
"Exchange Agreement"), a copy of which is attached hereto as Exhibit "1" and, by
this reference, made a part hereof; and

         WHEREAS,  the  parties  hereto  now  desire  to  rescind  the  Exchange
Agreement and revoke the terms and conditions set forth therein and transfer and
return to their prior  beneficial  owners all assets and property  that may have
been transferred pursuant to the terms of the Exchange Agreement.

         NOW,  THEREFORE,  in  consideration of the mutual  representations  and
covenants herein contained, the parties hereby agree as follows:

         1. The parties to this Rescission  Agreement  hereby  individually  and
jointly agree that the Exchange  Agreement will be rescinded and deemed null and
void,  effective  immediately,  and  that  all  terms,  conditions,   covenants,
representations  and  warranties  contained  in  said  Exchange  Agreement  will
terminate  immediately and will be deemed null and void and of no further effect
whatsoever.

         2. CMTI, as the wholly owned  subsidiary of ATI, and  Shareholders,  by
affixing their signatures to Schedule "A," agree that as  consideration  for the
execution of this Rescission Agreement, Shareholders will relinquish and forever
waive any ownership  claim or right to the 4,947,000  shares of ATI common stock
that were issued to the Shareholders or their designees pursuant to the terms of
the Exchange Agreement, and CMTI and Shareholders further agree to return to ATI
all  certificates  representing  the 4,947,000  shares of ATI common stock to be
cancelled  on the  stock  transfer  records  of ATI.  ATI  also  agrees  that as
consideration for the execution of this Rescission Agreement, it will relinquish
and forever  waive any  ownership  claim or right to the CMTI capital stock that
was  delivered  to ATI as  consideration  for the  issuance of ATI common  stock
pursuant  to the terms of the  Exchange  Agreement,  and will return to CMTI and
Shareholders all certificates representing such shares.

         3. It is further  agreed by the parties  hereto that the  aggregate  of
4,491,000  shares of ATI common stock issued pursuant to the Exchange  Agreement
to H. Deworth Williams,  Edward F. Cowle and Geoff Williams for certain services
related to the  negotiation  and  execution  of the Exchange  Agreement  and the
transactions  contemplated  thereby,  will  not be  returned  to ATI and will be
retained by Messrs.  Williams,  Cowle and  Williams as  consideration  for their
services rendered.

         4. All parties to this Rescission  Agreement  hereby agree that any and
all assets, tangible and intangible property,  securities or items of value that
may have been  assigned or  transferred  pursuant  to the terms of the  Exchange
Agreement  are  to  be,  immediately  upon  the  execution  of  this  Rescission
Agreement,  transferred  and reconveyed to the respective  parties that assigned
and/or transferred such items under the terms of the Exchange Agreement.

         5.  CMTI  represents  and  warrants  that  there  have been no debts or
liabilities  incurred by it in the name of or which encumbered the ATI corporate
entity  between the date of the Exchange  Agreement  and the date hereof and, in
the event any such debt  and/or  liability  has been  incurred  during such time
period,  CMTI  agrees to assume and become  obligated  in full for any such debt
and/or liability.  CMTI also represents and warrants that it has not sold and/or
issued any shares of ATI capital stock,  for valid  consideration  or otherwise,
between the date of the Exchange  Agreement  and the date  hereof.  CMTI further
agrees to indemnify and hold  harmless ATI against any debt,  liability or other
obligation  that may have been incurred by CMTI between the date of the Exchange
Agreement and the date hereof.

         6.  ATI  represents  and  warrants  that  there  have  been no debts or
liabilities  incurred  by it in the  name  of,  or  which  encumbered  the  CMTI
corporate entity between the date of the Exchange  Agreement and the date hereof
and, in the event any such debt and/or  liability has been incurred  during such
time period,  ATI agrees to assume and become  obligated to any such debt and/or
liability.  ATI further  agrees to indemnify  and hold harmless CMTI against any
debt,  liability or other  obligation that may have been incurred by ATI between
the date of the Exchange Agreement and the date hereof.


<PAGE>

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         7.  Immediately  prior to the execution of this  Rescission  Agreement,
Martin  Howard and Brian  Erickson  will tender to the Board of Directors  their
written  resignations  as  directors  and/or  executive  officers of ATI and the
remaining  director,  Edward  F.  Cowle,  will  at his  discretion  appoint  new
directors to the ATI Board of Directors. Such resignations will become effective
as of the date hereof and will be annexed  hereto as Exhibits and become part of
this Rescission Agreement.

         8.  As  soon as  practical  after  the  execution  of  this  Rescission
Agreement,  ATI will take the requisite corporate action to change its corporate
name. ATI further agrees and hereby grants to CMTI the unencumbered right to all
future uses of the name Cementitious Materials, Inc.

         9. All parties  hereto shall bear their  respective  costs and expenses
associated with the Exchange Agreement and this Rescission Agreement.

         10. All parties hereto agree to cooperate and use their best efforts in
taking all  necessary  and  requisite  actions to execute  and  effectuate  this
Rescission  Agreement and any other related documents in order to accomplish the
transaction contemplated hereby.

         11.  This  Rescission  Agreement  shall be  governed by the laws of the
State of Nevada. Any action to enforce the provisions of this Agreement shall be
brought within the State of Nevada and in no other place.

         12.  This  Rescission   Agreement  may  be  executed  in  one  or  more
counterparts,  each of which  shall be deemed an  original  and  together  shall
constitute one document. The delivery by facsimile of an executed counterpart of
this  Rescission  Agreement shall be deemed to be an original and shall have the
full force and effect of an original executed copy.

         IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Rescission  Agreement in a manner legally binding upon them as of the date first
written above.

           "ATI"
Cementitious Materials, Inc.



By: /s/ Edward F. Cowle
    ------------------------------------
Its:    Chairman

            "CMTI"
Cementitious Material Technologies, Inc.



By: /s/ Martin Howard
    ------------------------------------
Its:    President


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<TABLE>
<CAPTION>

                                  SCHEDULE "A"
<S>                                                                            <C>
"Shareholders" of Cementitious Material Technologies, Inc.                      No. of Shares
----------------------------------------------------------                      -------------



_____________________________________                                           1,387,573
The Piazza Family Trust, Matthew Piazza, Trustee



_____________________________________                                           1,387,573
Maiello Family Trust, Michael Maiello, Trustee



_____________________________________                                             482,634
Padre Cement LLC, Martin Howard, Mgr.



_____________________________________                                           1,085,927
DCKP LLC, by Douglas Cascella, Mgr.



_____________________________________                                              60,329
Karlik Family Partnership 3,
Patricia Karlik, General Partner



_____________________________________                                              60,329
Jim Phillips & Margitta Phillips



_____________________________________                                             120,659
Heidi Wymbs



_____________________________________                                             120,659
Barry Rehurek



_____________________________________                                             241,317
David M. Peluchette


                  TOTAL                                                         4,947,000
</TABLE>