BORATES, CARBONATES, NITRATES

Minerals in the borate class feature boron-oxygen groups that can connect through polymerization, creating chains, sheets, and various isolated structures. Similar to how silicates' silicon-oxygen (SiO4) tetrahedrons link up, the borates' (BO3)3– triangular groups also form connections. A single oxygen atom acts as a bridge between two boron cations (B3+), allowing the BO3 groups to form larger structures like double triangles, triple rings, sheets, and chains. This is possible because the small boron cation has a bond strength with oxygen that is precisely half of the bond energy of the oxygen ion.