• Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • AI SuperconnectorNEW
  • Settings
  • RSS Feeds
Quantisnow Logo
  • Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • AI SuperconnectorNEW
  • Settings
  • RSS Feeds
PublishGo to AppAI Superconnector
    Quantisnow Logo

    © 2025 quantisnow.com
    Democratizing insights since 2022

    Services
    Live news feedsRSS FeedsAlertsPublish with Us
    Company
    AboutQuantisnow PlusContactJobsAI superconnector for talent & startupsNEWLLM Arena
    Legal
    Terms of usePrivacy policyCookie policy

    Amendment: SEC Form SCHEDULE 13G/A filed by Novagold Resources Inc.

    11/13/25 11:41:55 AM ET
    $NG
    Precious Metals
    Basic Materials
    Get the next $NG alert in real time by email



    SECURITIES AND EXCHANGE COMMISSION
    Washington, D.C. 20549


    SCHEDULE 13G


    UNDER THE SECURITIES EXCHANGE ACT OF 1934
    (Amendment No. 1)


    Novagold Resources Inc.

    (Name of Issuer)


    Common Shares, no par value

    (Title of Class of Securities)


    66987E206

    (CUSIP Number)


    09/30/2025

    (Date of Event Which Requires Filing of this Statement)


    Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
    Checkbox checked   Rule 13d-1(b)
    Checkbox not checked   Rule 13d-1(c)
    Checkbox not checked   Rule 13d-1(d)






    SCHEDULE 13G

    CUSIP No.
    66987E206


    1Names of Reporting Persons

    Kopernik Global Investors, LLC
    2Check the appropriate box if a member of a Group (see instructions)

    Checkbox not checked  (a)
    Checkbox checked  (b)
    3Sec Use Only
    4Citizenship or Place of Organization

    DELAWARE
    Number of Shares Beneficially Owned by Each Reporting Person With:
    5Sole Voting Power

    0.00
    6Shared Voting Power

    22,754,680.00
    7Sole Dispositive Power

    0.00
    8Shared Dispositive Power

    24,003,695.00
    9Aggregate Amount Beneficially Owned by Each Reporting Person

    24,003,695.00
    10Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

    Checkbox not checked
    11Percent of class represented by amount in row (9)

    5.81 %
    12Type of Reporting Person (See Instructions)

    IA

    Comment for Type of Reporting Person:  "Shared Dispositive Power" and "Aggregate amount beneficially owned by each reporting person" includes 6,375,000 Common Shares that Kopernik Global Investors, LLC has the right to acquire pursuant to warrants. "Percentage of class represented by amount in Row (11)" is based on 413,301,988 Common Shares outstanding which is the sum of (i) 406,926,988 Common Shares outstanding as set forth in the Issuer's Form 10-Q for the fiscal quarter ended August 31, 2025 filed with the Securities and Exchange Commission on October 01, 2025 and (ii) 6,375,00 Common Shares issuable upon the exercise of the warrants.


    SCHEDULE 13G

    CUSIP No.
    66987E206


    1Names of Reporting Persons

    David B. Iben
    2Check the appropriate box if a member of a Group (see instructions)

    Checkbox not checked  (a)
    Checkbox checked  (b)
    3Sec Use Only
    4Citizenship or Place of Organization

    UNITED STATES
    Number of Shares Beneficially Owned by Each Reporting Person With:
    5Sole Voting Power

    0.00
    6Shared Voting Power

    22,754,680.00
    7Sole Dispositive Power

    0.00
    8Shared Dispositive Power

    24,003,695.00
    9Aggregate Amount Beneficially Owned by Each Reporting Person

    24,003,695.00
    10Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

    Checkbox not checked
    11Percent of class represented by amount in row (9)

    5.81 %
    12Type of Reporting Person (See Instructions)

    HC

    Comment for Type of Reporting Person:  "Shared Dispositive Power" and "Aggregate amount beneficially owned by each reporting person" includes 6,375,000 Common Shares that Kopernik Global Investors, LLC has the right to acquire pursuant to warrants. "Percentage of class represented by amount in Row (11)" is based on 413,301,988 Common Shares outstanding which is the sum of (i) 406,926,988 Common Shares outstanding as set forth in the Issuer's Form 10-Q for the fiscal quarter ended August 31, 2025 filed with the Securities and Exchange Commission on October 01, 2025 and (ii) 6,375,00 Common Shares issuable upon the exercise of the warrants.


    SCHEDULE 13G

    Item 1. 
    (a)Name of issuer:

    Novagold Resources Inc.
    (b)Address of issuer's principal executive offices:

    201 South Main Street, Suite 400, Salt Lake City, Utah
    Item 2. 
    (a)Name of person filing:

    This Schedule 13G is jointly filed by Kopernik Global Investors, LLC ("Kopernik Global Investors") and David B. Iben (collectively, the "Reporting Persons"). Kopernik Global Investors is an investment adviser. Mr. Iben is the controlling member and Chief Investment Officer of Kopernik Global Investors.
    (b)Address or principal business office or, if none, residence:

    2502 N Rocky Point Drive, Suite 300 Tampa, FL 33607
    (c)Citizenship:

    Kopernik Global Investors is a limited liability company organized under the laws of Delaware. Mr. Iben is a citizen of the United States of America.
    (d)Title of class of securities:

    Common Shares, no par value
    (e)CUSIP No.:

    66987E206
    Item 3.If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
    (a)Checkbox not checked   Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
    (b)Checkbox not checked   Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
    (c)Checkbox not checked   Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
    (d)Checkbox not checked   Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
    (e)Checkbox checked   An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
    (f)Checkbox not checked   An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
    (g)Checkbox checked   A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
    (h)Checkbox not checked   A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
    (i)Checkbox not checked   A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
    (j)Checkbox not checked   A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
           please specify the type of institution:
    (k)Checkbox not checked   Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
     
    Item 4.Ownership
    (a)Amount beneficially owned:

    The Reporting Persons beneficially own, in the aggregate, 24,003,695 Common Shares. None of the securities are held by the Reporting Persons. The filing of this statement shall not be construed as an admission that either of the Reporting Persons is the beneficial owner of any of the securities covered by this Schedule 13G for any other purpose.
    (b)Percent of class:

    The number of Common Shares beneficially owned by the Reporting Persons represents 5.81% of the Issuer's outstanding Common Shares based on 406,926,988 common shares outstanding as set forth in the Issuer's Form 10-Q for the fiscal quarter ended August 31, 2025 filed with the Securities and Exchange Commission on October 01, 2025, and 6,375,000 warrants.
    (c)Number of shares as to which the person has:
     (i) Sole power to vote or to direct the vote:

    0

     (ii) Shared power to vote or to direct the vote:

    22,754,680

     (iii) Sole power to dispose or to direct the disposition of:

    0

     (iv) Shared power to dispose or to direct the disposition of:

    24,003,695

    Item 5.Ownership of 5 Percent or Less of a Class.
     
    Item 6.Ownership of more than 5 Percent on Behalf of Another Person.
     
    If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.


    Securities reported on this Schedule 13G are beneficially owned by investment advisory clients which may include investment companies registered under the Investment Company Act and/or other separately managed accounts. No such person beneficially owns over 5%.
    Item 7.Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
     
    Not Applicable
    Item 8.Identification and Classification of Members of the Group.
     
    Not Applicable
    Item 9.Notice of Dissolution of Group.
     
    Not Applicable

    Item 10.Certifications:
     
    By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

        SIGNATURE 
     
    After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

     
    Kopernik Global Investors, LLC
     
    Signature:/s/ Sarah L. Bertrand
    Name/Title:Sarah L. Bertrand General Counsel and Chief Compliance Officer
    Date:11/13/2025
     
    David B. Iben
     
    Signature:/s/ David B. Iben by Sarah L. Bertrand, power of attorney
    Name/Title:David B. Iben by Sarah L. Bertrand, power of attorney
    Date:11/13/2025
    Exhibit Information

    99.1 Joint Filing Agreement, dated February 12, 2025, by and between Kopernik Global Investors, LLC and David B. Iben is incorporated herein by reference to Exhibit 99.1 of Schedule 13G filed with he SEC via EDGAR Accession No. 0000930413-25-000538 on February 12, 2025. 99.2 Power of Attorney appointing Sarah L. Bertrand, dated October 25, 2024, signed by David B. Iben is incorporated herein by reference to Exhibit 99.2 of Schedule 13G filed with he SEC via EDGAR Accession No. 0000930413-25-000538 on February 12, 2025.

    Get the next $NG alert in real time by email

    Crush Q3 2025 with the Best AI Superconnector

    Stay ahead of the competition with Standout.work - your AI-powered talent-to-startup matching platform.

    AI-Powered Inbox
    Context-aware email replies
    Strategic Decision Support
    Get Started with Standout.work

    Recent Analyst Ratings for
    $NG

    DatePrice TargetRatingAnalyst
    11/4/2025Outperform
    BMO Capital Markets
    10/29/2025Sector Perform → Outperform
    National Bank Financial
    7/16/2025$7.00Buy
    Citigroup
    6/4/2025$7.00Sector Perform → Outperform
    RBC Capital Mkts
    7/20/2022Outperform
    National Bank Financial
    2/7/2022Sector Perform
    RBC Capital Mkts
    More analyst ratings

    $NG
    SEC Filings

    View All

    Amendment: SEC Form SCHEDULE 13G/A filed by Novagold Resources Inc.

    SCHEDULE 13G/A - NOVAGOLD RESOURCES INC (0001173420) (Subject)

    11/13/25 11:41:55 AM ET
    $NG
    Precious Metals
    Basic Materials

    SEC Form 10-Q filed by Novagold Resources Inc.

    10-Q - NOVAGOLD RESOURCES INC (0001173420) (Filer)

    10/1/25 8:01:22 AM ET
    $NG
    Precious Metals
    Basic Materials

    Novagold Resources Inc. filed SEC Form 8-K: Results of Operations and Financial Condition, Regulation FD Disclosure, Financial Statements and Exhibits

    8-K - NOVAGOLD RESOURCES INC (0001173420) (Filer)

    10/1/25 8:01:28 AM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Analyst Ratings

    Analyst ratings in real time. Analyst ratings have a very high impact on the underlying stock. See them live in this feed.

    View All

    BMO Capital Markets initiated coverage on NovaGold Resources

    BMO Capital Markets initiated coverage of NovaGold Resources with a rating of Outperform

    11/4/25 8:38:12 AM ET
    $NG
    Precious Metals
    Basic Materials

    NovaGold Resources upgraded by National Bank Financial

    National Bank Financial upgraded NovaGold Resources from Sector Perform to Outperform

    10/29/25 12:30:58 PM ET
    $NG
    Precious Metals
    Basic Materials

    Citigroup initiated coverage on NovaGold Resources with a new price target

    Citigroup initiated coverage of NovaGold Resources with a rating of Buy and set a new price target of $7.00

    7/16/25 7:58:18 AM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Insider Trading

    Insider transactions reveal critical sentiment about the company from key stakeholders. See them live in this feed.

    View All

    President and CEO Lang Gregory A. was granted 2,934 shares, increasing direct ownership by 3% to 107,923 units (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    9/30/25 12:56:28 PM ET
    $NG
    Precious Metals
    Basic Materials

    Vice President & COO Williams Richard Alan was granted 1,483 shares, increasing direct ownership by 0.33% to 449,792 units (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    9/30/25 12:54:41 PM ET
    $NG
    Precious Metals
    Basic Materials

    Vice President & CFO Adamek Peter was granted 1,365 shares, increasing direct ownership by 16% to 9,694 units (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    9/30/25 12:53:10 PM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Press Releases

    Fastest customizable press release news feed in the world

    View All

    NOVAGOLD Files Third Quarter 2025 Report

    Successfully completed the transformative $1 billion acquisition1 of Barrick Mining Corporation's ("Barrick Mining") 50 percent interest in Donlin Gold on June 3, 2025, where NOVAGOLD increased its stake in Donlin Gold LLC to 60 percent, acquiring an additional 10 percent interest for $200 million, while funds managed by Paulson Advisers LLC ("Paulson") secured a 40 percent interest for $800 million.Announced the full exercise of the underwriters' option in the public offering on June 5, 2025, raising an additional $25.6 million as part of the financing at $3.75 per share.Strengthened the treasury of $125 million in cash and term deposits at the end of the third quarter with proceeds from th

    10/1/25 8:00:00 AM ET
    $NG
    Precious Metals
    Basic Materials

    SAVE THE DATE: NOVAGOLD 2025 Third Quarter Report, Conference Call and Video Webcast

    VANCOUVER, British Columbia, Sept. 10, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or "the Company" (NYSE American, TSX: NG) will release its 2025 third quarter report before market open on October 1, 2025, followed by a conference call and video webcast to discuss the results at 8:00 am PT (9:00 am MT/11:00 am ET). During the webcast, NOVAGOLD's Chairman, Dr. Thomas S. Kaplan, and President and Chief Executive Officer, Greg Lang, will provide a comprehensive update on the Company's 2025 third quarter activities, including the Donlin Gold drill program, community outreach, environmental initiatives, and advancement toward the Bankable Feasibility Study. Additionally, Pete

    9/10/25 5:05:00 PM ET
    $NG
    Precious Metals
    Basic Materials

    NOVAGOLD's 2025 Donlin Gold Drill Program Returns High-Grade Gold Intercepts, Strengthens Resource Conversion, and Supports Bankable Feasibility Study Progression

    Exceptional Drill Results: Drill results confirm consistent mineralization across multiple zones, including standout intervals up to 23.49 g/t gold, reinforcing Donlin Gold's position as one of the most significant gold development projects globally.Strategic Resource Conversion: Following the landmark $1 billion transaction with Paulson Advisers LLC ("Paulson"), the 2025 drill program pivoted to focus on conversion of resources and geotechnical work to support the Bankable Feasibility Study (BFS) — bringing new scale and momentum to the project.Donlin Gold BFS Bids: The Request for Proposal (RFP) for the BFS was issued to top-tier qualified engineering firms, with selection expected in the

    9/8/25 5:05:00 PM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Insider Purchases

    Insider purchases reveal critical bullish sentiment about the company from key stakeholders. See them live in this feed.

    View All

    Director Schutt Ethan bought $20,000 worth of shares (3,824 units at $5.23), increasing direct ownership by 8% to 51,735 units (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    7/29/25 10:31:31 AM ET
    $NG
    Precious Metals
    Basic Materials

    Director Kyle Hume D. bought $41,000 worth of shares (10,000 units at $4.10), increasing direct ownership by 81% to 22,348 units (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    7/1/25 1:08:53 PM ET
    $NG
    Precious Metals
    Basic Materials

    Large owner Electrum Strategic Resources L.P. bought $50,000,002 worth of shares (13,333,334 units at $3.75) (SEC Form 4)

    4 - NOVAGOLD RESOURCES INC (0001173420) (Issuer)

    5/9/25 4:49:46 PM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Leadership Updates

    Live Leadership Updates

    View All

    NOVAGOLD Announces Appointment of New Director

    VANCOUVER, British Columbia, July 21, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or the "Company") ((NYSE American, TSX:NG) is pleased to announce that the Company's Board of Directors (the "Board") has approved the appointment of Ali Erfan to serve on the Board effective immediately. Mr. Erfan's ascension will fill the vacancy left by the departure of director Diane Garrett. "I am very pleased to welcome Ali Erfan to NOVAGOLD's Board", said Dr. Thomas S. Kaplan, NOVAGOLD's Chairman. "Mr. Erfan brings a wealth of knowledge and experience as a long-standing Vice-Chairman of The Electrum Group, investment adviser to Electrum Strategic Resources, which is the Company's larg

    7/21/25 7:40:52 PM ET
    $NG
    Precious Metals
    Basic Materials

    NOVAGOLD Announces Election of Directors and Voting Results from 2025 Virtual Annual General Meeting of Shareholders

    A total of 275,809,182 or 82.41% of the Company's issued and outstanding shares were represented at the MeetingAll three proposals to shareholders were approved, including the election of all director nomineesDuring the 2025 proxy season, NOVAGOLD placed outreach calls to shareholders holding approximately 89.92% of the Company's issued and outstanding common shares entitled to vote VANCOUVER, British Columbia, May 20, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or the "Company") ((NYSE American, TSX:NG) is pleased to announce the detailed voting results on the items of business considered at its Annual General Meeting of Shareholders held on May 15, 2025 (the "Meeting").

    5/20/25 5:05:00 PM ET
    $NG
    Precious Metals
    Basic Materials

    NOVAGOLD Welcomes Peter Adamek as New Chief Financial Officer

    VANCOUVER, British Columbia, June 20, 2024 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or the "Company") ((NYSE American, TSX:NG) is pleased to announce the appointment of Peter Adamek as Vice President and Chief Financial Officer (CFO) of the Company effective July 15, 2024. The appointment of Mr. Adamek comes following the retirement of NOVAGOLD's long-serving CFO, David Ottewell, capping off a successful career in the mining sector. Mr. Ottewell will stay on until July 15, 2024 to ensure a seamless transition. "On behalf of NOVAGOLD, I wish to extend my sincere gratitude to David for his loyalty to the Company over the last 12 years," said Greg Lang, President and Chief Exe

    6/20/24 5:05:46 PM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Large Ownership Changes

    This live feed shows all institutional transactions in real time.

    View All

    Amendment: SEC Form SC 13G/A filed by Novagold Resources Inc.

    SC 13G/A - NOVAGOLD RESOURCES INC (0001173420) (Subject)

    11/14/24 5:16:48 PM ET
    $NG
    Precious Metals
    Basic Materials

    Amendment: SEC Form SC 13G/A filed by Novagold Resources Inc.

    SC 13G/A - NOVAGOLD RESOURCES INC (0001173420) (Subject)

    11/13/24 2:05:28 PM ET
    $NG
    Precious Metals
    Basic Materials

    Amendment: SEC Form SC 13G/A filed by Novagold Resources Inc.

    SC 13G/A - NOVAGOLD RESOURCES INC (0001173420) (Subject)

    11/12/24 1:00:04 PM ET
    $NG
    Precious Metals
    Basic Materials

    $NG
    Financials

    Live finance-specific insights

    View All

    SAVE THE DATE: NOVAGOLD 2025 Third Quarter Report, Conference Call and Video Webcast

    VANCOUVER, British Columbia, Sept. 10, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or "the Company" (NYSE American, TSX: NG) will release its 2025 third quarter report before market open on October 1, 2025, followed by a conference call and video webcast to discuss the results at 8:00 am PT (9:00 am MT/11:00 am ET). During the webcast, NOVAGOLD's Chairman, Dr. Thomas S. Kaplan, and President and Chief Executive Officer, Greg Lang, will provide a comprehensive update on the Company's 2025 third quarter activities, including the Donlin Gold drill program, community outreach, environmental initiatives, and advancement toward the Bankable Feasibility Study. Additionally, Pete

    9/10/25 5:05:00 PM ET
    $NG
    Precious Metals
    Basic Materials

    SAVE THE DATE: NOVAGOLD 2025 Second Quarter Report, Conference Call and Video Webcast

    VANCOUVER, British Columbia, June 13, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or "the Company" (NYSE American, TSX: NG) will release its 2025 second quarter report before market open on June 25, 2025, followed by a conference call and video webcast to discuss the results at 8:00 am PT (9:00 am MT/11:00 am ET). During the webcast, NOVAGOLD's Chairman, Dr. Thomas S. Kaplan, and President and Chief Executive Officer, Greg Lang, will deliver an update on the Company's recent transaction, outlining the strategic implications and impact on operations. They will also provide insights into key developments and ongoing activities within the Company.   Additionally, Peter Adame

    6/13/25 5:15:00 PM ET
    $NG
    Precious Metals
    Basic Materials

    NOVAGOLD Announces Date of its 2025 Virtual Annual Meeting of Shareholders

    NOVAGOLD's Annual General Meeting of Shareholders will be held virtually on May 15, 2025, at 1:00 p.m. PDTShareholders may vote on matters before the Meeting by proxy, join the virtual Meeting and vote, and submit questions either during the webcast or in advance by emailFollowing the Meeting, Chairman Dr. Thomas Kaplan and President and CEO Greg Lang will host a virtual presentation centered on the Donlin Gold project, a premier Tier 1 gold development project1 VANCOUVER, British Columbia, April 30, 2025 (GLOBE NEWSWIRE) -- NOVAGOLD RESOURCES INC. ("NOVAGOLD" or "the Company") ((NYSE American, TSX:NG) will hold the Company's 2025 Annual General Meeting of Shareholders on May 15, 2025, at

    4/30/25 8:00:00 AM ET
    $NG
    Precious Metals
    Basic Materials