Commitments and Contingencies	9 Months Ended
Mar. 31, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies Purchase Obligations As of March 31, 2026, the Company had purchase order commitments of approximately $2.0 million primarily for raw materials for the operation of the SSF; wellfield materials; engineering services and vendor testing related to the design of the proposed commercial-scale facility; consulting and services; environmental testing and other corporate services. Litigation Construction Services On July 17, 2023, the Company filed a complaint (the “Complaint”) against a previous construction contractor in the United States District Court for the Central District of California, Eastern Division, alleging, among other things, breaches by the contractor of its contractual obligations to 5EBA under the Procurement and Construction Contract, effective April 26, 2022, relating to the construction of the SSF. On August 10, 2023, the contractor filed an answer to the Complaint and asserted counterclaims against 5EBA seeking relief of approximately $5.5 million. On March 17, 2026, the parties executed a settlement agreement resolving all claims and counterclaims related to the matter, and the Company paid a settlement amount of approximately $4.3 million. The Company had previously accrued $2.8 million related to probable amounts owed under the construction contract and, upon approval of the settlement, recorded an additional $1.5 million to property, plant and equipment, which will be depreciated prospectively over the remaining useful life of the SSF. Refer to Note 4-Property, Plant and Equipment, for additional details. Mining Claims On May 11, 2026, Elementis Specialties Inc. (“Elementis”) filed a complaint in the United States District Court for the Central District of California, Eastern Division, captioned Elementis Specialties Inc. v. 5E Advanced Materials, Inc. et al., Case No. 5:26-cv-02488, against the Company and its wholly owned subsidiary, 5EBA. The complaint alleges, among other things, claims for quiet title, trespass, declaratory relief, slander of title, and violation of California’s unfair competition law relating to certain federal unpatented mining claims in San Bernardino County, California. Elementis seeks declaratory and injunctive relief, quiet title, compensatory and consequential damages in an amount to be proven at trial, punitive damages, statutory penalties, attorneys’ fees, costs, and interest. The Company believes it has defensible claims, disputes the allegations, and intends to vigorously defend the matter. Based on information currently available and management’s current assessment, the Company is unable to reasonably estimate possible damages or a range of possible damages and has not recorded an accrual related to this matter in the accompanying unaudited condensed consolidated financial statements.

Commitments and Contingencies

9 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

13. Commitments and Contingencies

Purchase Obligations

As of March 31, 2026, the Company had purchase order commitments of approximately $2.0 million primarily for raw materials for the operation of the SSF; wellfield materials; engineering services and vendor testing related to the design of the proposed commercial-scale facility; consulting and services; environmental testing and other corporate services.

Litigation

Construction Services

On July 17, 2023, the Company filed a complaint (the “Complaint”) against a previous construction contractor in the United States District Court for the Central District of California, Eastern Division, alleging, among other things, breaches by the contractor of its contractual obligations to 5EBA under the Procurement and Construction Contract, effective April 26, 2022, relating to the construction of the SSF. On August 10, 2023, the contractor filed an answer to the Complaint and asserted counterclaims against 5EBA seeking relief of approximately $5.5 million.

On March 17, 2026, the parties executed a settlement agreement resolving all claims and counterclaims related to the matter, and the Company paid a settlement amount of approximately $4.3 million. The Company had previously accrued $2.8 million related to probable amounts owed under the construction contract and, upon approval of the settlement, recorded an additional $1.5 million to property, plant and equipment, which will be depreciated prospectively over the remaining useful life of the SSF. Refer to Note 4-Property, Plant and Equipment, for additional details.

Mining Claims

On May 11, 2026, Elementis Specialties Inc. (“Elementis”) filed a complaint in the United States District Court for the Central District of California, Eastern Division, captioned Elementis Specialties Inc. v. 5E Advanced Materials, Inc. et al., Case No. 5:26-cv-02488, against the Company and its wholly owned subsidiary, 5EBA. The complaint alleges, among other things, claims for quiet title, trespass, declaratory relief, slander of title, and violation of California’s unfair competition law relating to certain federal unpatented mining claims in San Bernardino County, California. Elementis seeks declaratory and injunctive relief, quiet title, compensatory and consequential damages in an amount to be proven at trial, punitive damages, statutory penalties, attorneys’ fees, costs, and interest. The Company believes it has defensible claims, disputes the allegations, and intends to vigorously defend the matter. Based on information currently available and management’s current assessment, the Company is unable to reasonably estimate possible damages or a range of possible damages and has not recorded an accrual related to this matter in the accompanying unaudited condensed consolidated financial statements.