Khosla leads $310M Series B for mining startup Mariana Minerals at $1.5B valuation
What's the deal? Mariana Minerals, a San Francisco software-focused mining startup, has raised a $310 million Series B led by Khosla Ventures. The round values the company at $1.5 billion and brings its total raised to $400 million.
Who else is in? Longtime backer Andreessen Horowitz joined, alongside Breakthrough Energy VenturesDealroom has a profile for this one. Try Dealroom →, Greenoaks, Halo Fund, Pax VenturesDealroom has a profile for this one. Try Dealroom →, StepStone Group, BHP VenturesDealroom has a profile for this one. Try Dealroom →, Washington Harbour PartnersDealroom has a profile for this one. Try Dealroom →, Greycroft, and Mitsubishi CorporationDealroom has a profile for this one. Try Dealroom →.
What's the endgame? Mariana, founded in 2024 by former Tesla factory engineer Turner Caldwell with Baker Tilney and Juan Lozano, runs mines using autonomous software. Its Copper One site in Utah — a restarted idled mine — is moving toward 50,000 metric tons of refined copper a year; its Lithium One site in Texas is expected to reach commercial production in 2027.
The pitch is cost. "Our goal is to reduce the cost of these core inputs to the modern economy over time," said Caldwell, who wants a software backbone "as generalizable as possible" across copper, lithium, aluminium, nickel, cobalt, uranium, and rare earths.
Why now? China controls as much as 90% of critical minerals processing worldwide, a chokehold that has put US supply chains at risk. Mariana is betting that surging metals demand from the AI buildout — data centres, chips, grids, and robots all start with copper — makes an efficient, software-based miner essential.
What could go wrong? Mariana is a two-year-old startup entering a centuries-old sector dominated by incumbents such as BHP GroupDealroom has a profile for this one. Try Dealroom → and Standard LithiumDealroom has a profile for this one. Try Dealroom →. Its Lithium One production timeline runs to 2027, meaning much of the thesis remains unproven.
The signal: This is an unusually large early-stage round — among the top 1% of all Series B deals in US energy on record. It signals investor conviction that reshoring critical minerals, and doing it with automation, has become a strategic priority tied directly to the AI boom.
Read more: PRN
Image credit: Mariana Minerals
