Minerals described in 1999

Walfordite is a very rare tellurite mineral that was discovered in Chile in 1999. The mineral is described as orange with orange-yellow streak, and is determined to have a chemical formula of Fe3+,Te6+Te4+3O8 with minor titanium and magnesium substitution resulting in an approximate empirical formula of (Fe3+,Te6+,Ti4+,Mg)(Te4+)3O8.

Changoite is a rare zinc sulfate mineral with the formula Na2Zn(SO4)2·4H2O. Chagoite was discovered in the San Francisco Mine near Sierra Gorda, Antofagasta, Chile. The mineral is a zinc-analogue of blödite, cobaltoblödite, manganoblödite and nickelblödite - other representatives of the blödite group. In terms of chemistry changoite is somewhat similar to gordaite. The mineral's name comes from the Chango people, a group of early inhabitants of northern Chile.

Strontiomelane is an oxide mineral from the coronadite group in the hollandite supergroup. Specimens of the mineral appear very similar to other manganese oxides from the same group, such as the Ba-analogue hollandite. The type locality is the Praborna mine in Saint-Marcel, Italy.

Ferrokentbrooksite is a moderately rare mineral of the eudialyte group, with formula . The original formula was extended form to show the presence of cyclic silicate groups and presence of silicon at the M4 site, according to the nomenclature of eudialyte group. As suggested by its name, it is the (ferrous) iron analogue of kentbrooksite. When compared to the latter, it is also chlorine-dominant instead of being fluorine-dominant. The original (holotype) material is also relatively enriched in rare earth elements, including cerium and yttrium.