Trona crystals
with Tincalconite (white) from Trona, CA (Searles Lake). Specimen measures
about 7" from left to right.
Close up picture on the left and a microscopic view (10X) on the right.
CHEMISTRY - Na3H(CO3)2.2H2O
CRYSTALLOGRAPHY - Monoclinic Prismatic
CRYSTAL GROWTH AND HABITS - Trona often forms fibrous to acicular crystals. It can also produce columnar crystals or be massive. Well formed crystals are rare.
COLOR AND OPTICAL PROPERTIES - Usually colorless to gray or yellowish. It is transparent to translucent.
HARDNESS - 2.5 - 3
SPECIFIC GRAVITY - 2.14
LUSTER - Vitreous
STREAK - White
BREAKABILITY - Trona has a perfect cleavage along {100} and an uneven to subconchoidal fracture.
OCCURRENCE - Found in saline lakes and as surface deposits in arid climate soils.
ASSOCIATED MINERALS - Halite, Hanksite, Glauberite, Thenardite, Mirabilite, Gypsum, Borax (Tincalconite).
MINERAL NAME - Derived from a discarded Arabic word for native salt (natron which became tron). The town of Trona, California was named after the mineral Trona.