EXHIBIT 4.1

THESE  SECURITIES AND THE SECURITIES  ISSUABLE UPON THEIR EXERCISE HAVE NOT BEEN
REGISTERED  UNDER THE SECURITIES  ACT OF 1933 AND MAY NOT BE TRANSFERRED  UNLESS
COVERED BY AN  EFFECTIVE  REGISTRATION  STATEMENT  UNDER SAID ACT, A "NO ACTION"
LETTER  FROM  THE  SECURITIES  AND  EXCHANGE  COMMISSION  WITH  RESPECT  TO SUCH
TRANSFER,  A TRANSFER MEETING THE REQUIREMENTS OF RULE 144 OF THE SECURITIES AND
EXCHANGE COMMISSION,  OR AN OPINION OF COUNSEL SATISFACTORY TO THE ISSUER TO THE
EFFECT THAT ANY SUCH TRANSFER IS EXEMPT FROM SUCH REGISTRATION.

                              XYBERNAUT CORPORATION

                          COMMON STOCK PURCHASE WARRANT

                  1.   Issuance.   In   consideration   of  good  and   valuable
consideration,  the  receipt  of  which  is  hereby  acknowledged  by  Xybernaut
Corporation,  a Delaware  corporation  (the "Company"),  Crystalite  Investments
Ltd.,  or  registered  assigns  (the  "Holder")  is hereby  granted the right to
purchase  at any time until 5:00  P.M.,  New York City time,  on October 1, 2004
(the "Expiration  Date"),  One Million  (1,000,000) fully paid and nonassessable
shares of the  Company's  Common  Stock,  par value $.01 per share (the  "Common
Stock") at an initial exercise price of $1.01 per share (the "Exercise  Price"),
subject to further adjustment as set forth in Section 6 hereof.

                  2. Exercise of Warrants.  This Warrant is exercisable in whole
or in part at the Exercise  Price per share of Common Stock  payable  hereunder,
payable  in cash  or by  certified  or  official  bank  check,  or by  "cashless
exercise",  by means of  tendering  this Warrant  Certificate  to the Company to
receive  a number  of  shares  of  Common  Stock  equal in  Market  Value to the
difference  between the Market Value of the shares of Common Stock issuable upon
exercise  of this  Warrant  and the total  cash  exercise  price  thereof.  Upon
surrender of this Warrant  Certificate  with the annexed Notice of Exercise Form
duly  executed,  together  with payment of the Exercise  Price for the shares of
Common Stock purchased, the Holder shall be entitled to receive a certificate or
certificates  for the shares of Common Stock so  purchased.  For the purposes of
this Section 2, "Market  Value" shall be an amount equal to the average  closing
bid  price of a share  of  Common  Stock  for the ten (10)  days  preceding  the
Company's receipt of the Notice of Exercise Form duly executed multiplied by the
number of shares of Common  Stock to be issued upon  surrender  of this  Warrant
Certificate.

                  3.  Reservation  of Shares.  The Company hereby agrees that at
all times during the term of this  Warrant  there shall be reserved for issuance
upon exercise of this Warrant such number of shares of its Common Stock as shall
be required for issuance upon exercise of this Warrant (the "Warrant Shares").



<PAGE>


                  4. Mutilation or Loss of Warrant.  Upon receipt by the Company
of evidence satisfactory to it of the loss, theft,  destruction or mutilation of
this  Warrant,  and (in the  case of  loss,  theft or  destruction)  receipt  of
reasonably  satisfactory  indemnification,  and (in the case of mutilation) upon
surrender and cancellation of this Warrant, the Company will execute and deliver
a new  Warrant of like tenor and date and any such lost,  stolen,  destroyed  or
mutilated Warrant shall thereupon become void.

                  5.  Rights of the  Holder.  The Holder  shall  not,  by virtue
hereof, be entitled to any rights of a stockholder in the Company, either at law
or equity,  and the rights of the Holder are limited to those  expressed in this
Warrant and are not  enforceable  against  the Company  except to the extent set
forth herein.

                  6.       Protection Against Dilution.

                         6.1  Adjustment  Mechanism.  If an  adjustment  of  the
Exercise  Price is  required  pursuant  to this  Section 6, the Holder  shall be
entitled to purchase  such number of  additional  shares of Common Stock as will
cause (i) the total  number of shares  of Common  Stock  Holder is  entitled  to
purchase  pursuant to this  Warrant,  multiplied  by (ii) the adjusted  purchase
price per share,  to equal (iii) the dollar amount of the total number of shares
of Common Stock Holder is entitled to purchase before  adjustment  multiplied by
the total purchase price before adjustment.

                         6.2 Capital Adjustments.  In case of any stock split or
reverse  stock split,  stock  dividend,  reclassification  of the Common  Stock,
recapitalization,  merger or consolidation, or like capital adjustment affecting
the Common  Stock of the  Company,  the  provisions  of this  Section 6 shall be
applied as if such capital  adjustment event had occurred  immediately  prior to
the date of this  Warrant  and the  original  purchase  price  had  been  fairly
allocated  to the stock  resulting  from such capital  adjustment;  and in other
respects the  provisions of this Section  shall be applied in a fair,  equitable
and reasonable manner so as to give effect, as nearly as may be, to the purposes
hereof.  A rights offering to  stockholders  shall be deemed a stock dividend to
the extent of the bargain purchase element of the rights.

                  7. Transfer to Comply with the  Securities  Act;  Registration
Rights.

                  (a) This Warrant has not been registered  under the Securities
Act of 1933,  as  amended,  (the  "Act")  and has been  issued to the Holder for
investment and not with a view to the  distribution of either the Warrant or the
Warrant Shares.  Neither this Warrant nor any of the Warrant Shares or any other
security  issued  or  issuable  upon  exercise  of  this  Warrant  may be  sold,
transferred, pledged or hypothecated in the absence of an effective registration
statement  under the Act  relating  to such  security  or an  opinion of counsel
satisfactory  to the Company that  registration  is not required  under the Act.
Each  certificate  for the Warrant,  the Warrant  Shares and any other  security
issued or issuable  upon  exercise of this Warrant shall contain a legend on

<PAGE>

the face thereof, in form and substance satisfactory to counsel for the Company,
setting forth the restrictions on transfer contained in this Section.

                  (b)  The  Company  hereby  grants  to  the  Holder   piggyback
registration rights with respect to the Warrant Shares. In the event the Company
is  filing a  Registration  Statement  for  itself  or on  behalf  of any of its
shareholders,  the  Company  shall  notify the Holder in writing  reasonably  in
advance of such filing (but at least five business days) and give the Holder the
opportunity  to include all or any party of the Warrant  Shares  (whether or not
previously  issued,  to the extent  permissible  under the Act or any regulation
promulgated  thereunder.  Upon the Holder's notification that the Holder desires
to have all or any portion of the Warrant Shares included in such  registration,
the Company shall,  at no cost or expense to the Holder,  include or cause to be
included in such registration  statement the Warrant Shares so identified by the
Holder.

                  (c) In addition to the registration  rights referred to in the
preceding  provisions  of Section (b),  effective  after the  expiration  of the
effectiveness of the Registration  Statement as contemplated by the Registration
Rights Agreement,  the Holder shall have demand piggy-back  registration  rights
with  respect to the Warrant  Shares then held by the Holder or then  subject to
issuance upon exercise of this Warrant  (collectively,  the  "Remaining  Warrant
Shares"),  subject to the conditions set forth below.  If, at any time after the
Registration  Statement  has ceased to be  effective,  the Company  participates
(whether  voluntarily  or by reason of an  obligation  to a third  party) in the
registration  of any  shares of the  Company's  stock,  the  Company  shall give
written  notice  thereof  to the  Holder  and the  Holder  shall have the right,
exercisable  within ten (10)  business  days after  receipt of such  notice,  to
demand inclusion of all or a portion of the Holder's Remaining Warrant Shares in
such registration statement.

                  8.  Notices.  Any notice or other  communication  required  or
permitted  hereunder  shall be in  writing  and shall be  delivered  personally,
telegraphed,  telexed,  sent by  facsimile  transmission  or sent by  certified,
registered or express mail,  postage  pre-paid.  Any such notice shall be deemed
given when so delivered  personally,  telegraphed,  telexed or sent by facsimile
transmission,  or, if  mailed,  two days after the date of deposit in the United
States mails, as follows:

                           (i)      if the to Company, to:

                                    Xybernaut Corporation
                                    12701 Fair Lakes Circle
                                    Suite 550
                                    Fairfax, Virginia 22033
                                    Fax no.: 703-631-6734
                                    Attn: Chief Financial Officer
<PAGE>

                           (ii)     if to the Holder, to:
                                    Crystalite Investments, Ltd.
                                    111 Arlosorov Street
                                    Tel Aviv, Israel
                                    Fax no.: 011-972-3-691-0476


Any party may be  notice  given in  accordance  with this  Section  to the other
parties designate another address or person for receipt of notices hereunder.

                  9. Supplements and Amendments;  Whole Agreement.  This Warrant
may be amended or  supplemented  only by an instrument in writing  signed by the
parties   hereto.   This  Warrant  of  even  date  herewith   contain  the  full
understanding  of the parties  hereto with respect to the subject  matter hereof
and  thereof  and  there  are  no  representations,  warranties,  agreements  or
understandings other than expressly contained herein and therein.

                  10.  Governing  Law.  This  Warrant  shall be  deemed  to be a
contract made under the laws of the State of New York and for all purposes shall
be  governed  by and  construed  in  accordance  with  the  laws of  such  State
applicable to contracts to be made and performed entirely within such State.

                  11.  Counterparts.  This Warrant may be executed in any number
of counterparts and each of such  counterparts  shall for all purposes be deemed
to be an original,  and all such counterparts shall together  constitute but one
and the same instrument.

                  12. Descriptive Headings.  Descriptive headings of the several
Sections of this Warrant are inserted for convenience only and shall not control
or affect the meaning or construction of any of the provisions hereof.


<PAGE>



         IN WITNESS WHEREOF, the parties hereto have executed this Warrant as of
the __th day of December 1999.


                                    XYBERNAUT CORPORATION



                                    By:_______________________________________
                                             Name: Steven A. Newman
                                             Title:   Vice Chairman

Attest:


------------------------------
------------------------------
Chief Administrative Officer



<PAGE>



                                     FORM OF
                          NOTICE OF EXERCISE OF WARRANT

         The  undersigned  hereby  irrevocably  elects to  exercise  the  right,
represented by the Warrant Certificate dated as of __________, 1999, to purchase
__________  shares of the Common Stock,  par value $.01 per share,  of Xybernaut
Corporation  and tenders  herewith  payment in accordance with Section 1 of said
Common Stock Purchase Warrant.

         Please deliver the stock certificate to:





Dated:

                                          CRYSTALITE INVESTMENTS, LTD.


                                           By:__________________________________