Brilliant Earth Group, Inc.

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

On March 10, 2026, the Company approved a revised form of indemnification and advancement agreement (the “Indemnification Agreement”) governed by Nevada law, which the Company plans to enter into with its directors, officers and certain of its employees. The Indemnification Agreement supersedes the Company’s prior form of indemnification agreement. The full text of the form of Indemnification Agreement is attached hereto as Exhibit 10.16 to this Annual Report on Form 10-K.

b. Insider Trading Arrangements and Policies

During the three months ended December 31, 2025, 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 November 24, 2025, 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)July 31, 2026, (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.