Natron
Na₂CO₃ · 10H₂O

     Natron is relatively rare at MSH. Once exposed to air, it alters very rapidly to thermonatrite.

PHYSICAL CHARACTERISTICS:

Color is usually colorless.
Luster is dull.
Diaphaneity is transparent.
Crystal System is monoclinic; Cc.
Crystal Habits include crystalline masses to 4cm, rarely anhedral
   crystals.
Cleavage {001} is distinct and {010} is imperfect.
Fracture is conchoidal.
Hardness is 1.
Specific Gravity is approximately 1.5 g/cm³.
Streak is white.
Associated Minerals include ussingite, villiaumite and most of the
   species found in sodalite xenoliths.
Distinguishing Features: Color and alteration to thermonatrite.
Origin: Named in antiquity from the Hebraic neter, alkaline salts,
   referring to its sodium content.

CLASSIFICATION:

REFERENCES:
MinRec 21:325 (1990), Dana 8:462-463 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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