Brimstone
Transforming Industry
Oakland, United States · Founded 2019 · $21.5M raised
- Headquarters
- Oakland, California
- Employees
- 51–200
- Founded
- 2019
- Business Model
- B2B
- Website
- brimstone.com
- Total Funding
- $21.5M
- Last Round
- $21.0M Venture RoundAug 2025
- Rounds
- 3
About
Brimstone is a deep tech company developing the Rock Refinery, a patented co-production process that refines calcium-bearing silicate rock into portland cement, supplementary cementitious materials (SCM), alumina, and other industrial materials. The process eliminates CO2 emissions tied to limestone calcination, which accounts for the majority of cement's carbon footprint, while delivering cost-competitive products at industrial scale.
Summary
Brimstone is a Climate Tech company based in Oakland, United States, founded in 2019. It has raised $21.5M in total across 3 rounds, most recently a $21.0M Venture Round round in Aug 2025. Investors include Kajima Ventures.
Tech & App Stack
2 technologies & apps tracked
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Funding History
Aug 2025
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Grant through Venture Round — per-round amounts, valuations, and who invested in each round.
Investors
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