Brilliant Earth Group, Inc.

(a) None.

(b) None.

(c) Except as described below, during the three months ended September 30, 2026, no directors or “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 August 14, 2026, Sharon Dziesietnik, the Company's Chief Operations Officer, adopted a Rule 10b5-1 trading arrangement (the "Dziesietnik 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 an aggregate of up to 56,832 shares of the Company's Class A common stock (a portion of the shares of Class A common stock to be received by Ms. Dziesietnik upon the vesting of restricted stock units as set forth in the Dziesietnik Sales Plan) to cover estimated tax obligations in connection with the vesting and settlement of restricted stock units. The Dziesietnik Sales Plan will remain in effect until the earliest of (1)August 30, 2027, (2) the date on which all trades set forth in the Dziesietnik Sales Plan have been executed, or (3) such time as the Dziesietnik Sales Plan is otherwise terminated or expires according to its terms.

On September 14, 2026, Jeffrey Kuo, the Company's Chief Financial Officer, adopted a Rule 10b5-1 trading arrangement (the "Kuo 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 an aggregate of up to 39,673 shares of the Company's Class A common stock (a portion of the shares of Class A common stock to be received by Mr. Kuo upon the vesting of restricted stock units as set forth in the Kuo Sales Plan) to cover estimated tax obligations in connection with the vesting and settlement of restricted stock units. The Kuo Sales Plan will remain in effect until the earliest of (1)May 25, 2027, (2) the date on which all trades set forth in the Kuo Sales Plan have been executed, or (3) such time as the Kuo Sales Plan is otherwise terminated or expires according to its terms.