Barium-bearing minerals

In an extensive review of the geochemistry of volatile-bearing minerals in mantle xenoliths, Ionov et al (1997) have pointed out that although minerals such as mica, amphibole, and apatite are often referred to as hydrous, in many cases they have very low H2O contents (Boettcher and O Neill, 1980). In such cases, these minerals may have significant amounts of fluorine, chlorine and CO2. Mica, amphibole, and apatite, together with the oxide phases, are important hosts for titanium, potassium, rubidium, strontium, barium, and niobium (Table 9). 

Ferraris G, Khomyakov AP, Belluso E, Soboleva SV (1998) Kalifersite, a new alkaline silicate from Kola Peninsula (Russia) based on a palygorskite-sepiolite polysomatic series. Eur J Mineial 10 865-874 Filut MA, Rule AC, Bailey SW (1985) Ciystal stincture refinement of anandite-20r, a barium- and suUur-bearing trioctahedral mica. Am Mineral 70 1298-1308... 

---