Probertite is a calcium-sodium borate mineral used in certain specialty applications, especially where a mixed-cation borate is advantageous for formulations in ceramics, adhesives, and select chemical syntheses. Production is generally limited to mines with specific evaporite or hydrothermal conditions producing mixed borate suites. Probertite output is often a component of broader borate production rather than a primary commodity, meaning availability is tied to the economics of recovering multiple borate species from ore. Over recent years production has been relatively stable but constrained—few new probertite-specific projects exist, and recovery tends to be opportunistic. Price behavior shows a niche premium relative to basic sodium borates because buyers value the mixed calcium-sodium chemistry.