Exhibit
4.2


 


NEITHER THESE SECURITIES NOR THE SECURITIES
ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION
OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES
ACT”) AND APPLICABLE STATE SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO (I) AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR (II) AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT
TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS.
THESE SECURITIES AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN
ACCOUNT OR OTHER LOAN SECURED BY SUCH SECURITIES.


 


AQUA METALS, INC.


 


WARRANT TO PURCHASE COMMON STOCK


 


	Warrant No. 1	 	
        Original Issue Date:

        September 8, 2014



 


Aqua Metals, Inc., a Delaware corporation
(the “Company”), hereby certifies that, for value received, Liquid Patent Consulting, LLC or its permitted
registered assigns (the “Holder”), is entitled to purchase from the Company up to a total of 100 shares
of common stock, no par value (the “Common Stock”), of the Company (each such share, a “Warrant
Share” and all such shares, the “Warrant Shares”) at an exercise price per share equal
to $15.00 (as adjusted from time to time as provided in Section 9 herein, the “Exercise Price”), at any
time and from time to time from on or after the date hereof (the “Trigger Date”) and through and including
5:00 P.M., prevailing Pacific time, on September 8, 2017 (the “Expiration Date”), and subject to the
following terms and conditions:


 


This Warrant (this
“Warrant”) is one of a series of similar warrants issued pursuant to that certain Engagement Agreement
for Strategic Consulting Services dated September 8, 2014 between the Company and the Holder (the “Consulting Agreement”).
All such warrants are referred to herein, collectively, as the “Warrants.”


 


1.            Definitions.
In addition to the terms defined elsewhere in this Warrant, capitalized terms that are not otherwise defined herein have the meanings
given to such terms in the Consulting Agreement.


 




    	 



    	 



    

  


2.            Registration
of Warrants. The Company shall register this Warrant, upon records to be maintained by the Company for that purpose (the “Warrant
Register”), in the name of the record Holder (which shall include the initial Holder or, as the case may be, any
registered assignee to which this Warrant is permissibly assigned hereunder) from time to time. The Company may deem and treat
the registered Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any distribution to
the Holder, and for all other purposes, absent actual notice to the contrary.


 


3.            Registration
of Transfers. The Company shall register the transfer of all or any portion of this Warrant in the Warrant Register, upon (i)
surrender of this Warrant, with the Form of Assignment attached as Schedule 2 hereto duly completed and signed, to the Company’s
transfer agent or to the Company at its address specified herein (ii) delivery, at the request of the Company, of an opinion of
counsel reasonably satisfactory to the Company to the effect that the transfer of such portion of this Warrant may be made pursuant
to an available exemption from the registration requirements of the Securities Act of 1933 (“Securities Act”)
and all applicable state securities or blue sky laws and (iii) delivery by the transferee of a written statement to the Company
certifying that the transferee is an “accredited investor” as defined in Rule 501(a) under the Securities Act and making
the representations and certifications as the Company may reasonably request to procure an exemption from section 5 of the Securities
Act. Upon any such registration or transfer, a new warrant to purchase Common Stock in substantially the form of this Warrant (any
such new warrant, a “New Warrant”) evidencing the portion of this Warrant so transferred shall be issued
to the transferee, and a New Warrant evidencing the remaining portion of this Warrant not so transferred, if any, shall be issued
to the transferring Holder. The acceptance of the New Warrant by the transferee thereof shall be deemed the acceptance by such
transferee of all of the rights and obligations of a Holder of a Warrant.


 


4.            Exercise
and Duration of Warrants.


 


(a)       All
or any part of this Warrant shall be exercisable by the registered Holder at any time and from time to time on or after the Trigger
Date and through and including 5:00 P.M. prevailing Pacific time on the Expiration Date. At 5:00 P.M., prevailing Pacific time,
on the Expiration Date, the portion of this Warrant not exercised prior thereto shall be and become void and of no value and this
Warrant shall be terminated and no longer outstanding.


 


(b)       The
Holder may exercise this Warrant by delivering to the Company (i) an exercise notice, in the form attached as Schedule 1 hereto
(the “Exercise Notice”), appropriately completed and duly signed, (ii) payment of the Exercise Price
for the number of Warrant Shares as to which this Warrant is being exercised (which may take the form of a “cashless exercise”
if so indicated in the Exercise Notice and if a “cashless exercise” may occur at such time pursuant to Section 10 below),
and the date such items are delivered to the Company (as determined in accordance with the notice provisions hereof) is an “Exercise
Date.” The Holder shall not be required to deliver the original Warrant in order to effect an exercise hereunder.
Execution and delivery of the Exercise Notice shall have the same effect as cancellation of the original Warrant and issuance of
a New Warrant evidencing the right to purchase the remaining number of Warrant Shares.


 




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5.            Delivery
of Warrant Shares. Upon exercise of this Warrant, the Company shall promptly issue or cause to be issued and cause to be delivered
to or upon the written order of the Holder and in such name or names as the Holder may designate a certificate for the Warrant
Shares issuable upon such exercise, with an appropriate restrictive legends. The Holder, or any Person permissibly so designated
by the Holder to receive Warrant Shares, shall be deemed to have become the holder of record of such Warrant Shares as of the Exercise
Date.


 


6.            Charges,
Taxes and Expenses. Issuance and delivery of certificates for shares of Common Stock upon exercise of this Warrant shall be
made without charge to the Holder for any issue or transfer tax, transfer agent fee or other incidental tax or expense in respect
of the issuance of such certificates, all of which taxes and expenses shall be paid by the Company; provided, however, that
the Company shall not be required to pay any tax which may be payable in respect of any transfer involved in the registration of
any certificates for Warrant Shares or Warrants in a name other than that of the Holder or an Affiliate thereof. The Holder shall
be responsible for all other tax liability that may arise as a result of holding or transferring this Warrant or receiving Warrant
Shares upon exercise hereof.


 


7.            Replacement
of Warrant. If this Warrant is mutilated, lost, stolen or destroyed, the Company shall issue or cause to be issued in exchange
and substitution for and upon cancellation hereof, or in lieu of and substitution for this Warrant, a New Warrant, but only upon
receipt of evidence reasonably satisfactory to the Company of such loss, theft or destruction (in such case) and, in each case,
a customary and reasonable indemnity (which shall not include a surety bond), if requested. Applicants for a New Warrant under
such circumstances shall also comply with such other reasonable regulations and procedures and pay such other reasonable third-party
costs as the Company may prescribe. If a New Warrant is requested as a result of a mutilation of this Warrant, then the Holder
shall deliver such mutilated Warrant to the Company as a condition precedent to the Company’s obligation to issue the New
Warrant.


 


8.            Reservation
of Warrant Shares. The Company covenants that it will at all times reserve and keep available out of the aggregate of its authorized
but unissued and otherwise unreserved Common Stock, solely for the purpose of enabling it to issue Warrant Shares upon exercise
of this Warrant as herein provided, the number of Warrant Shares which are then issuable and deliverable upon the exercise of this
entire Warrant, free from preemptive rights or any other contingent purchase rights of persons other than the Holder (taking into
account the adjustments and restrictions of Section 9). The Company covenants that all Warrant Shares so issuable and deliverable
shall, upon issuance and the payment of the applicable Exercise Price in accordance with the terms hereof, be duly and validly
authorized, issued and fully paid and nonassessable. The Company will take all such action as may be necessary to assure that such
shares of Common Stock may be issued as provided herein without violation of any applicable law or regulation, or of any requirements
of any securities exchange or automated quotation system upon which the Common Shares may be listed.


 




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9.            Certain
Adjustments. The Exercise Price and number of Warrant Shares issuable upon exercise of this Warrant are subject to adjustment
from time to time as set forth in this Section 9.


 


(a)       Stock
Dividends and Splits. If the Company, at any time while this Warrant is outstanding, (i) pays a stock dividend on its Common
Stock or otherwise makes a distribution on any class of capital stock that is payable in shares of Common Stock, (ii) subdivides
its outstanding shares of Common Stock into a larger number of shares, or (iii) combines its outstanding shares of Common Stock
into a smaller number of shares, then in each such case the Exercise Price shall be multiplied by a fraction, the numerator of
which shall be the number of shares of Common Stock outstanding immediately before such event and the denominator of which shall
be the number of shares of Common Stock outstanding immediately after such event. Any adjustment made pursuant to clause (i) of
this paragraph shall become effective immediately after the record date for the determination of stockholders entitled to receive
such dividend or distribution, and any adjustment pursuant to clause (ii) or (iii) of this paragraph shall become effective immediately
after the effective date of such subdivision or combination.


 


(b)       Fundamental
Transactions. If, at any time while this Warrant is outstanding (i) the Company effects any merger or consolidation of
the Company with or into another Person, in which the Company is not the survivor, (ii) the Company effects any sale of all or
substantially all of its assets or a majority of its Common Stock is acquired by a third party, in each case, in one or a series
of related transactions, (iii) any tender offer or exchange offer (whether by the Company or another Person) is completed pursuant
to which all or substantially all of the holders of Common Stock are permitted to tender or exchange their shares for other securities,
cash or property, or (iv) the Company effects any reclassification of the Common Stock or any compulsory share exchange pursuant
to which the Common Stock is effectively converted into or exchanged for other securities, cash or property (other than as a result
of a subdivision or combination of shares of Common Stock covered by Section 9(a) above) (in any such case, a “Fundamental
Transaction”), then the Holder shall have the right thereafter to receive, upon exercise of this Warrant, the same
amount and kind of securities, cash or property as it would have been entitled to receive upon the occurrence of such Fundamental
Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of the number of Warrant Shares then
issuable upon exercise in full of this Warrant without regard to any limitations on exercise contained herein (the “Alternate
Consideration”). The Company shall not effect any such Fundamental Transaction unless prior to or simultaneously
with the consummation thereof, any successor to the Company, surviving entity or the corporation purchasing or otherwise acquiring
such assets or other appropriate corporation or entity shall assume the obligation to deliver to the Holder, such Alternate Consideration
as, in accordance with the foregoing provisions, the Holder may be entitled to purchase and/or receive (as the case may be), and
the other obligations under this Warrant. The provisions of this paragraph (c) shall similarly apply to subsequent transactions
analogous to a Fundamental Transaction.


 




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(c)       Number
of Warrant Shares. Simultaneously with any adjustment to the Exercise Price pursuant to paragraph (a) of this Section, the
number of Warrant Shares that may be purchased upon exercise of this Warrant shall be increased or decreased proportionately, so
that after such adjustment the aggregate Exercise Price payable hereunder for the increased or decreased number of Warrant Shares
shall be the same as the aggregate Exercise Price in effect immediately prior to such adjustment.


 


(d)       Calculations.
All calculations under this Section 9 shall be made to the nearest cent or the nearest 1/100th of a share, as
applicable. The number of shares of Common Stock outstanding at any given time shall not include shares owned or held by or for
the account of the Company, and the sale or issuance of any such shares shall be considered an issue or sale of Common Stock.


 


(e)       Notice
of Adjustments. Upon the occurrence of each adjustment pursuant to this Section 9, the Company at its expense will,
at the written request of the Holder, promptly compute such adjustment, in good faith, in accordance with the terms of this Warrant
and prepare a certificate setting forth such adjustment, including a statement of the adjusted Exercise Price and adjusted number
or type of Warrant Shares or other securities issuable upon exercise of this Warrant (as applicable), describing the transactions
giving rise to such adjustments and showing in detail the facts upon which such adjustment is based. Upon written request, the
Company will promptly deliver a copy of each such certificate to the Holder and to the Company’s transfer agent.


 




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(f)       Notice
of Corporate Events. If, while this Warrant is outstanding, the Company (i) declares a dividend or any other distribution
of cash, securities or other property in respect of its Common Stock, including, without limitation, any granting of rights or
warrants to subscribe for or purchase any capital stock of the Company, (ii) authorizes or approves, enters into any agreement
contemplating or solicits stockholder approval for any Fundamental Transaction or (iii) authorizes the voluntary dissolution, liquidation
or winding up of the affairs of the Company, then, except if such notice and the contents thereof shall be deemed to constitute
material non-public information, the Company shall deliver to the Holder a notice describing the material terms and conditions
of such transaction at least ten (10) Trading Days prior to the applicable record or effective date on which a Person would need
to hold Common Stock in order to participate in or vote with respect to such transaction, and the Company will take all steps reasonably
necessary in order to insure that the Holder is given the practical opportunity to exercise this Warrant prior to such time so
as to participate in or vote with respect to such transaction; provided, however, that the failure to deliver such notice
or any defect therein shall not affect the validity of the corporate action required to be described in such notice.


 


10.            Payment
of Exercise Price. The Holder shall pay the Exercise Price in immediately available funds; provided, however, the Holder
may, in its sole discretion, commencing on the date that is 18 months from the date of this Warrant, satisfy its obligation to
pay the Exercise Price through a “cashless exercise”, in which event the Company shall issue to the Holder the number
of Warrant Shares determined as follows:


 


X = Y [(A-B)/A]


 


where:


 


X = the number of Warrant Shares
to be issued to the Holder.


 


Y = the total number of Warrant
Shares with respect to which this Warrant is being exercised.


 


A = the average of the Closing
Sale Prices of the shares of Common Stock (as reported by Bloomberg Financial Markets) for the five Trading Days ending on the
date immediately preceding the Exercise Date.


 


B = the Exercise Price then
in effect for the applicable Warrant Shares at the time of such exercise.


 




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For purposes of this Warrant, “Closing
Sale Price” means, for any security as of any date, the last trade price for such security on the principal securities
exchange or trading market for such security, as reported by Bloomberg Financial Markets, or, if such exchange or trading market
begins to operate on an extended hours basis and does not designate the last trade price, then the last trade price of such security
prior to 4:00:00 p.m., New York Time, as reported by Bloomberg Financial Markets, or if the foregoing do not apply, the last trade
price of such security in the over-the-counter market on the electronic bulletin board for such security as reported by Bloomberg
Financial Markets, or, if no last trade price is reported for such security by Bloomberg Financial Markets, the average of the
bid prices, or the ask prices, respectively, of any market makers for such security as reported in the "pink sheets"
by Pink Sheets LLC. If the Closing Sale Price cannot be calculated for a security on a particular date on any of the foregoing
bases, the Closing Sale Price of such security on such date shall be the fair market value as mutually determined by the Company
and the Holder. If the Company and the Holder are unable to agree upon the fair market value of such security, then the Company
shall, within two business days submit via facsimile (a) the disputed determination of the Warrant Exercise Price to an independent,
reputable investment bank selected by the Company and approved by the Holder or (b) the disputed arithmetic calculation of the
Warrant Shares to the Company's independent, outside accountant. The Company shall cause at its expense the investment bank or
the accountant, as the case may be, to perform the determinations or calculations and notify the Company and the Holder of the
results no later than ten business days from the time it receives the disputed determinations or calculations. Such investment
bank's or accountant's determination or calculation, as the case may be, shall be binding upon all parties absent demonstrable
error. All such determinations to be appropriately adjusted for any stock dividend, stock split, stock combination or other similar
transaction during the applicable calculation period.


 


For purposes of Rule 144 promulgated under
the Securities Act, it is intended, understood and acknowledged that the Warrant Shares issued in a cashless exercise transaction
shall be deemed to have been acquired by the Holder, and the holding period for the Warrant Shares shall be deemed to have commenced,
on the date this Warrant was originally issued pursuant to the Consulting Agreement (provided that the Commission continues to
take the position that such treatment is proper at the time of such exercise).


 




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11.          Limitation
on Exercises. In the event that the Company registers the sale of any of its securities pursuant to the Securities Act of 1933,
as amended, as an initial public offering, in an transaction that is subject FINRA review for compensation purposes, where the
Holder is, or an affiliate of, a distribution participant for the offering, then this Warrant may not be exercised for 90 days
after the effective date of the initial registration statement under that act. Additionally, the Company shall not effect the exercise
of this Warrant, and the Holder shall not have the right to exercise this Warrant, to the extent that after giving effect to such
exercise, the Holder (together with such Holder’s affiliates) would beneficially own in excess of 4.99% (“Maximum
Percentage”) of the shares of Common Stock outstanding immediately after giving effect to such exercise. For purposes
of the foregoing sentence, the aggregate number of shares of Common Stock beneficially owned by such Holder and its affiliates
shall include the number of shares of Common Stock issuable upon exercise of this Warrant with respect to which the determination
of such sentence is being made, but shall exclude shares of Common Stock which would be issuable upon (A) exercise of the remaining,
unexercised portion of this Warrant beneficially owned by such Holder and its affiliates and (B) exercise or conversion of the
unexercised or unconverted portion of any other securities of the Company beneficially owned by such Person and its affiliates
(including, without limitation, any convertible notes or convertible preferred stock or warrants) subject to a limitation on conversion
or exercise analogous to the limitation contained herein. Except as set forth in the preceding sentence, for purposes of this paragraph,
beneficial ownership shall be calculated in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended. To
the extent that the limitation contained in this Section 11 applies, the determination of whether this Warrant is exercisable (in
relation to other securities owned by the Holder together with any affiliate) and of which portion of this Warrant is exercisable
shall be in the sole discretion of the Holder, and the submission of a Notice of Exercise shall be deemed to be the Holder’s
determination of whether this Warrant is exercisable (in relation to other securities owned by the Holder together with any affiliate)
and of which portion of this Warrant is exercisable, in each case subject to such aggregate percentage limitation, and the Company
shall have no obligation to verify or confirm the accuracy of the determination. For purposes of this Warrant, in determining the
number of outstanding shares of Common Stock, the Holder may rely on the number of outstanding shares of Common Stock as reflected
in (1) the Company's most recent Form 10-K, Form 10-Q, Current Report on Form 8-K or other public filing with the Securities and
Exchange Commission, as the case may be, (2) a more recent public announcement by the Company or (3) any other notice by the Company
setting forth the number of shares of Common Stock outstanding. For any reason at any time, upon the written or oral request of
the Holder, the Company shall within one (1) business day confirm orally and in writing to the Holder the number of shares of Common
Stock then outstanding. In any case, the number of outstanding shares of Common Stock shall be determined after giving effect to
the conversion or exercise of securities of the Company, including this Warrant, by the Holder and its affiliates since the date
as of which such number of outstanding shares of Common Stock was reported. By written notice to the Company, any Holder may decrease
the Maximum Percentage to any other percentage specified in such notice; provided that such decrease will apply only to the Holder
sending such notice and not to any other holder of Warrants. In addition, by written notice to the Company, any Holder may remove
the limitations on exercises provided in this Section 11 entirely; provided that (i) any such removal will not be effective until
the 61st day after such notice is delivered to the Company, and (ii) any such removal will apply only to the Holder sending such
notice and not to any other holder of Warrants. The provisions of this paragraph shall be construed and implemented in a manner
otherwise than in strict conformity with the terms of this Section 11 to correct this paragraph (or any portion hereof) which may
be defective or inconsistent with the intended beneficial ownership limitation herein contained or to make changes or supplements
necessary or desirable to properly give effect to such limitation.


 




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12.          No
Fractional Shares. No fractional Warrant Shares will be issued in connection with any exercise of this Warrant. In lieu of
any fractional shares which would otherwise be issuable, the number of Warrant Shares to be issued shall be rounded up to the next
whole number.


 


13.          Notices.
Any and all notices or other communications or deliveries hereunder (including, without limitation, any Exercise Notice) shall
be in writing and shall be deemed given and effective on the earliest of (i) the date of transmission, if such notice or communication
is delivered via email at the email address specified in the Consulting Agreement prior to 5:00 p.m. (prevailing Pacific time)
on a Trading Day, (ii) the next Trading Day after the date of transmission, if such notice or communication is delivered via
email at the email address specified in the Consulting Agreement t on a day that is not a Trading Day or later than 5:00 p.m. (prevailing
Pacific time) on any Trading Day, (iii) the Trading Day following the date of mailing, if sent by nationally recognized overnight
courier service specifying next business day delivery, or (iv) upon actual receipt by the party to whom such notice is required
to be given, if by hand delivery. The address and facsimile number of a party for such notices or communications shall be as set
forth in the Consulting Agreement unless changed by such party by two Trading Days’ prior notice to the other party in accordance
with this Section 13.


 


14.         Warrant
Agent. The Company shall serve as warrant agent under this Warrant. Upon thirty (30) days’ notice to the Holder, the
Company may appoint a new warrant agent. Any corporation into which the Company or any new warrant agent may be merged or any corporation
resulting from any consolidation to which the Company or any new warrant agent shall be a party or any corporation to which the
Company or any new warrant agent transfers substantially all of its corporate trust or shareholders services business shall be
a successor warrant agent under this Warrant without any further act. Any such successor warrant agent shall promptly cause notice
of its succession as warrant agent to be mailed (by first class mail, postage prepaid) to the Holder at the Holder’s last
address as shown on the Warrant Register.


 


15.          Registration
Rights. The Company agrees that the Holder and its assigns will have registration rights covering the resale of the Warrant
Shares, including “piggyback” registration rights on the registrations of the Company or demand registrations
(voting with the other registrable securities to effect any such demand), no less favorable than those granted to any other person
by the Company prior or subsequent to the date of this Warrant. At such time, and from time to time, as the Company enters into
an agreement subsequent to the date of this Warrant pursuant to which the Company grants any third party rights with respect to
the Company’s registration of Company securities under the Securities Act held by such party, the Company shall offer to
enter into a formal written registration rights agreement with the Holder and its assigns on substantially the same terms and such
other terms as are customary and usual for agreements of such nature. In addition to, and without restricting or limiting the scope
of this subparagraph (a), the Company further agrees that:


 




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(a)       Right
to Piggyback. Whenever the Company proposes to register any of its securities under the Securities Act, the Company will give
prompt written notice to the Holder of its intention to effect such registration and will include in such registration all Warrant
Shares with respect to which the Company has received a written request from the Holder for inclusion therein within 15 days after
the receipt of the Company's notice. The Company will pay, or cause to be paid, the registration expenses of the Holder in all
piggyback registrations.


 


(b)       Underwritten
Offering. If a piggyback registration is an underwritten primary or secondary registration on behalf of the Company and/or
other holders of the Common Stock, and the managing underwriters advise the Company in writing that in their opinion the number
of shares requested to be included in such registration (including the Warrant Shares and any other shares of Common Stock held
by holders with registration rights) exceeds the number which can be sold in such offering without materially and adversely affecting
the marketability of the offering, the Company will promptly furnish the Holder with a copy of the underwriter's opinion and may,
by written notice to the Holder, include in such registration (i) first, the securities the Company proposes to sell, and (ii)
second, the Common Stock requested to be included in such registration pro rata among all holders with registration rights on the
basis of the number of shares owned by each such holder.


 


(c)       Underwriting
Agreement. In any registration in which the Warrant Shares is to be included, the Holder shall be a party to the underwriting
agreement entered into by the Company in connection therewith, and the representations and warranties by, and the other agreements
on the part of, the Company and for the benefit of the underwriters shall also be made to and for the benefit of the Holder.


 


(d)       Documents,
etc. The Company shall provide to the Holder any and all documents, statements, opinions and forms as the Holder reasonably
deems necessary for the Holder to participate in any piggyback registrations and to facilitate the disposition of the Warrant Shares
covered by such registration pursuant to the terms and conditions of this Agreement and the applicable securities laws.


 




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(e)       Indemnification.
In the event of any piggyback registration of any Warrant Shares under the Securities Act, and in connection with any registration
statement or any other disclosure document pursuant to which securities of the Company are sold, the Company will, and hereby does,
jointly and severally, indemnify and hold harmless the Holder, its directors, officers, members, fiduciaries, and agents (each,
a "Covered Person") against any losses, claims, damages or liabilities, joint or several, to which such
Covered Person may be or become subject under the Securities Act, any other securities or other laws of any jurisdiction, common
law or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) arise out
of or are based upon (1) any untrue statement or alleged untrue statement of any material fact contained or incorporated by reference
in any registration statement under the Securities Act, any preliminary prospectus or final prospectus included therein, or any
amendment or supplement thereto, or any document incorporated by reference therein, or any other such disclosure document, or (2)
any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statement
therein not misleading, and will reimburse such Covered Person for any legal or any other expenses incurred by in connection with
investigating or defending any such loss, claim, damage, liability, action or proceeding; provided, however, the
Company shall not be liable to any Covered Person in any such case to the extent that any such loss, claim, damage, liability,
action or proceeding arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission
made in such registration statement, any such preliminary prospectus, final prospectus, amendment or supplement, any document incorporated
by reference or other such disclosure document in reliance upon and in conformity with written information furnished to the Company
through an instrument duly executed by such Covered Person specifically stating this it is for use in the preparation thereof.


 


(f)       All
fees and expenses incurred by the Company in connection with the performance of its obligation to register the Warrant Shares pursuant
to Section 15 shall be borne by the Company; provided that any fees and expenses of the holder or holders thereof or of
its or their counsel, and transfer taxes applicable to the sale of such Warrant Shares, shall be borne by such holder or holders.


 


16.          Miscellaneous.


 


(a)       The
Holder, solely in such Person's capacity as a holder of this Warrant, shall not be entitled to vote or receive dividends or be
deemed the holder of share capital of the Company for any purpose, nor shall anything contained in this Warrant be construed to
confer upon the Holder, solely in such Person's capacity as the Holder of this Warrant, any of the rights of a stockholder of the
Company or any right to vote, give or withhold consent to any corporate action (whether any reorganization, issue of stock, reclassification
of stock, consolidation, merger, amalgamation, conveyance or otherwise), receive notice of meetings, receive dividends or subscription
rights, or otherwise, prior to the issuance to the Holder of the Warrant Shares which such Person is then entitled to receive upon
the due exercise of this Warrant. In addition, nothing contained in this Warrant shall be construed as imposing any liabilities
on the Holder to purchase any securities (upon exercise of this Warrant or otherwise) or as a stockholder of the Company, whether
such liabilities are asserted by the Company or by creditors of the Company. Notwithstanding this Section 16(a), the Company shall
provide the Holder with copies of the same notices and other information given to the shareholders of the Company, contemporaneously
with the giving thereof to the shareholders.


 




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(b)       Subject
to the restrictions on transfer set forth on the first page hereof, and compliance with applicable securities laws, this Warrant
may be assigned by the Holder. This Warrant may not be assigned by the Company except to a successor in the event of a Fundamental
Transaction. This Warrant shall be binding on and inure to the benefit of the parties hereto and their respective successors and
assigns. Subject to the preceding sentence, nothing in this Warrant shall be construed to give to any Person other than the Company
and the Holder any legal or equitable right, remedy or cause of action under this Warrant. This Warrant may be amended only in
writing signed by the Company and the Holder, or their successors and assigns.


 


(c)       GOVERNING
LAW; VENUE; WAIVER OF JURY TRIAL. ALL QUESTIONS CONCERNING THE CONSTRUCTION, VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS WARRANT
SHALL BE GOVERNED BY AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF THE STATE OF CALIFORNIA WITHOUT REGARD TO THE PRINCIPLES
OF CONFLICTS OF LAW THEREOF. EACH PARTY HEREBY IRREVOCABLY SUBMITS TO THE EXCLUSIVE JURISDICTION OF THE STATE AND FEDERAL COURTS
SITTING IN THE CITY OF LOS ANGELES, CALIFORNIA, FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR WITH
ANY TRANSACTION CONTEMPLATED HEREBY OR DISCUSSED HEREIN (INCLUDING WITH RESPECT TO THE ENFORCEMENT OF ANY OF THE TRANSACTION DOCUMENTS),
AND HEREBY IRREVOCABLY WAIVES, AND AGREES NOT TO ASSERT IN ANY SUIT, ACTION OR PROCEEDING, ANY CLAIM THAT IT IS NOT PERSONALLY
SUBJECT TO THE JURISDICTION OF ANY SUCH COURT, THAT SUCH SUIT, ACTION OR PROCEEDING IS IMPROPER. EACH PARTY HEREBY IRREVOCABLY
WAIVES PERSONAL SERVICE OF PROCESS AND CONSENTS TO PROCESS BEING SERVED IN ANY SUCH SUIT, ACTION OR PROCEEDING BY MAILING A COPY
THEREOF VIA REGISTERED OR CERTIFIED MAIL OR OVERNIGHT DELIVERY (WITH EVIDENCE OF DELIVERY) TO SUCH PARTY AT THE ADDRESS IN EFFECT
FOR NOTICES TO IT UNDER THIS AGREEMENT AND AGREES THAT SUCH SERVICE SHALL CONSTITUTE GOOD AND SUFFICIENT SERVICE OF PROCESS AND
NOTICE THEREOF. NOTHING CONTAINED HEREIN SHALL BE DEEMED TO LIMIT IN ANY WAY ANY RIGHT TO SERVE PROCESS IN ANY MANNER PERMITTED
BY LAW. THE COMPANY HEREBY WAIVES ALL RIGHTS TO A TRIAL BY JURY. 


 




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(d)        The
headings herein are for convenience only, do not constitute a part of this Warrant and shall not be deemed to limit or affect any
of the provisions hereof.


 


(e)        In
case any one or more of the provisions of this Warrant shall be invalid or unenforceable in any respect, the validity and enforceability
of the remaining terms and provisions of this Warrant shall not in any way be affected or impaired thereby, and the parties will
attempt in good faith to agree upon a valid and enforceable provision which shall be a commercially reasonable substitute therefor,
and upon so agreeing, shall incorporate such substitute provision in this Warrant.


 


(f)         Except
as otherwise set forth herein, prior to exercise of this Warrant, the Holder hereof shall not, by reason of by being a Holder,
be entitled to any rights of a stockholder with respect to the Warrant Shares.


 


[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,


SIGNATURE PAGE FOLLOWS]


 




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IN WITNESS WHEREOF, the Company has caused
this Warrant to be duly executed by its authorized officer as of the date first indicated above.


 


	AQUA METALS, INC.,
	A Delaware corporation
	 	 
	By:	/s/ Stephen R. Clarke
	 	Dr. Stephen R. Clarke,
	 	President and Chief Executive Officer



  




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SCHEDULE 1


FORM OF EXERCISE NOTICE


 


(To be executed by the Holder to exercise
the right to purchase shares of Common Stock under the foregoing Warrant)


 


Ladies and Gentlemen:


 


(1)       The
undersigned is the Holder of Warrant No. 1 (the “Warrant”) issued by Aqua Metals, Inc.., a Delaware corporation
(the “Company”). Capitalized terms used herein and not otherwise defined herein have the respective meanings
set forth in the Warrant.


 


(2)       The
undersigned hereby exercises its right to purchase __________ Warrant Shares pursuant to the Warrant.


 


(3)       The
Holder intends that payment of the Exercise Price shall be made as (check one):


 


		€	Cash
Exercise



 


		€	“Cashless
Exercise” under Section 10



 


(4)       If
the Holder has elected a Cash Exercise, the Holder shall pay the sum of $_______ in immediately available funds to the Company
in accordance with the terms of the Warrant.


 


(5)       Pursuant
to this Exercise Notice, the Company shall deliver to the Holder _____________ Warrant Shares in accordance with the terms of the
Warrant.


 


Dated:_______________, _____


Name of Holder: ___________________________


By:__________________________________

Name: _______________________________

Title: _______________________________


(Signature must conform in all respects
to name of Holder as specified on the face of the Warrant) 


 




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SCHEDULE 2


FORM OF ASSIGNMENT


 


[To be completed and signed only upon transfer
of Warrant]


 


FOR VALUE RECEIVED, the undersigned hereby
sells, assigns and transfers unto                             
(the “Transferee” the right represented by the within Warrant to purchase                 
shares of Common Stock of Aqua Metals, Inc. (the “Company”) to which the within Warrant relates and appoints
                            
attorney to transfer said right on the books of the Company with full power of substitution in the premises. In connection therewith,
the undersigned represents, warrants, covenants and agrees to and with the Company that:


(a)       the
offer and sale of the Warrant contemplated hereby is being made in compliance with Section 4(1) of the United States Securities
Act of 1933, as amended (the “Securities Act”) or another valid exemption from the registration requirements
of Section 5 of the Securities Act and in compliance with all applicable securities laws of the states of the United States;


(b)       the
undersigned has not offered to sell the Warrant by any form of general solicitation or general advertising, including, but not
limited to, any advertisement, article, notice or other communication published in any newspaper, magazine or similar media or
broadcast over television or radio, and any seminar or meeting whose attendees have been invited by any general solicitation or
general advertising;


(c)       the
undersigned has read the Transferee’s investment letter included herewith, and to its actual knowledge, the statements made
therein are true and correct; and


(d)       the
undersigned understands that the Company may condition the transfer of the Warrant contemplated hereby upon the delivery to the
Company by the undersigned or the Transferee, as the case may be, of a written opinion of counsel (which opinion shall be in form,
substance and scope customary for opinions of counsel in comparable transactions) to the effect that such transfer may be made
without registration under the Securities Act and under applicable securities laws of the states of the United States.


 


	Dated:             ,     	 	 
	 	 	(Signature must conform in all respects to name of holder as specified on the face of the Warrant)
	 	 	 
	 	 	 
	 	 	Address of Transferee
	 	 	 
	 	 	 
	 	 	 
	 	 	 


 


	In the presence of:
	 
	 


 








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