Brilliant Earth Group Inc

a. Disclosure in lieu of reporting on a Current Report on Form 8-K.

None.

b. Insider Trading Arrangements and Policies

During the three months ended December 31, 2024, the following directors and “officers” (as defined in Rule 16a-1(f) under the Exchange Act) of the Company adopted, modified orterminated “Rule 10b5-1 trading arrangements” and/or “non-Rule 10b5-1 trading arrangements” (each as defined in Item 408 of Regulation S-K).

On December 3, 2024, Jennifer Harris, a member of the Company’s Board of Directors, adopted a Rule 10b5-1 trading arrangement (the “Harris Sales Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act and which provides for the sale of up to an aggregate of 22,581 shares of Class A common stock (a portion of the shares of Class A common stock to be received by Ms. Harris upon the vesting of restricted stock units, as set forth in the Harris Sales Plan). The Harris Sales Plan will remain in effect until the earliest of (1) the close of business on the second business day after the initial trade date (on or within two business days after June 16, 2025), (2) the date on which an aggregate of 22,581 shares of Class A common stock have been sold under the Harris Sales Plan, or (3) such time as the Harris Sales Plan is otherwise terminated or expires according to its terms.

On December 11, 2024, Just Rocks, Inc., a Delaware corporation which is jointly owned and controlled by Beth Gerstein, the Company’s Chief Executive Officer and a member of the Board of Directors, and Eric Grossberg, the Company’s Executive Chairman, adopted a Rule 10b5-1 trading arrangement (the “Just Rocks Sales Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act and which provides for the sale of up to 700,000 shares of Class A common stock. The Just Rocks Sales Plan will remain in effect until the earliest of (1)November 14, 2025, (2) the date on which an aggregate of 700,000 shares of Class A common stock have been sold under the Just Rocks Sales Plan, or (3) such time as the Just Rocks Sales Plan is otherwise terminated or expires according to its terms.

On December 11, 2024, Mainsail Partners III, L.P., Mainsail Co-Investors III, L.P. and Mainsail Incentive Program, LLC (together, the “Mainsail Entities”)adopted a Rule 10b5-1 trading arrangement (the “Mainsail Sales Plan”) that is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act. Gavin Turner, a member of the Company’s Board of Directors, is the Managing Partner of Mainsail Management Company, LLC (“Mainsail Partners”) and may be deemed to have a pecuniary interest in the Class A common stock owned by the Mainsail Entities. The Mainsail Sales Plan provides for the sale of up to an aggregate of 1,000,000 shares of Class A common stock. The Mainsail Sales Plan will remain in effect until the earliest of (1)August 28, 2025, (2) the date on which an aggregate of 1,000,000 shares of Class A common stock have been sold under the Mainsail Sales Plan, or (3) such time as the Mainsail Sales Plan is otherwise terminated or expires according to its terms.