Senarmontite is, in some respects, an under appreciated mineral. It
is rather scarce and not very well distributed, so good specimens are hard
to find. It forms excellent octahedral crystals that can be transparent
with a high luster. Specimens with dozens of octahedrons of randomly varying
sizes are especially admirable.
Senarmontite is dimorphous with the mineral valentinite.
Both minerals have the exact same chemistry, but they have different structures.
Senarmontite is isometric
and valentinite is orthorhombic.
It is similar to the situation between diamond
Valentinite is associated with senarmontite as well as stibnite.
Actually both senarmontite and valentinite are oxidation products of
the antimony sulfide.
- Color is colorless, white or gray.
- Luster is vitreous, adamantine, greasy or resinous.
- Transparency: Crystals are translucent to transparent.
- Crystal System is isometric.
- Crystal Habits typically include well formed octahedral crystals
but more commonly massive as well as granular and encrusting.
- Cleavage is imperfect.
- Fracture is conchoidal.
- Hardness is 2 - 2.5
- Specific Gravity is approximately 5.3 - 5.5 (heavier than average).
- Streak is white.
- Associated Minerals include quartz, stibnite
kermesite, native antimony, stibiconite and other antimony minerals.
- Notable Occurrences are limited to the Djebel-Haminate Mine,
Ain Beida, Qacentina (Constantine), Algeria and Ham Sud Township, Wolfe
County, Quebec, Canada.
- Best Field Indicators are crystal habit, high luster, associations
and specific gravity.