Trona
Na3CO3(HCO3) · 2H2O

     Trona is almost identical in appearance to other species such as nahpoite, thermonatrite and dorfmanite which occur in the same environment and cannot be reliably identified by visual identification.

PHYSICAL CHARACTERISTICS:

Color is usually white.
Luster is dull.
Diaphaneity is translucent.
Crystal System is monoclinic; C2/c.
Crystal Habits include powdery aggregates and interstitial fillings.
Cleavage {100} is perfect.
Fracture is uneven.
Hardness is 2.5 - 3.
Specific Gravity is approximately 2.1 g/cm3.
Streak is white.
Associated Minerals include aegirine, calcite, fluorite, galena,
   pectolite, sodalite and villiaumite.
Distinguishing Features: None from other white powdery species.
Origin: Named in 1773 for the reduced form of the word for native
   salt in Arabic, natrun.

CLASSIFICATION:

Dana System
# 13.1.4.1

Strunz Classification
# V/D.02-30

REFERENCES:
MinRec 21:343 (1990), Dana 8:423-424 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
--

MX
--

SS
--

MC
--

HF
--

BR
--

SX
¤¤

FR
--

Legend