5. Mineralogy

There are some forty beryllium-containing minerals, all of which are more or less complex compounds. Only a few of these minerals have any actual or potential commercial value (table 8 ), with the exception of precious varieties such as emerald and aquamarine. However, given that beryllium can replace silicon by substitution in the crystal lattice, a further fifty or so occurrences must be added [31] .

Only beryl (14.0% BeO) and bertrandite (42.4% BeO) have an industrial outlet. Other minerals, such as barylite (15.4 to 15.8% BeO), chrysoberyl (16.7 to 19.7% BeO) and phenacite (44.0 to 45.6% BeO), despite their often high BeO content, do not yield ores with exploitable grades....