Crystal system: Hexagonal dipyramidal ditrigonal.         

Color: Blue to blue-green.  

Habit: Elongated prismatic, acicular, in divergent radial tufts, fibrous, crusts or felt-like aggregates, < 1 mm.

Cleavage: No. Striations paralell to [0001].

Tenacity: Brittle.       

Twinning: No.   

Fracture:  Splintery.

Mohs Hardness: 3

Parting: No.   

Streak: Pale green-blue. 

Lustre:  Sub-vitreous.

Diaphaneity: Transparent.     

Density (g/cm³): 3.36

2. Geology and Deposits

Connellite is part of the assemblage of secondary minerals that form in the oxidized zones of copper deposits.

Broadly speaking, secondary copper minerals include:

– black minerals (tenorite),

– red minerals (cuprite),

– green minerals (malachite, pseudomalachite, brochantite, antlerite, atacamite, dioptase, botallackite, libethenite, olivenite, duftite, and natrochalcite), and

– blue minerals (chrysocolla, cyanotrichite, plancheite, sampleite, linarite, caledonite, chalcanthite, shattuckite, liroconite, mrázekite, connellite, and kröhnkite).

Several of the blue minerals can appear green, and vice versa.

In various occurrences of connellite in Wales, the mineral originated post-mining, when tailings or slag from copper ore processing were exposed to a marine atmosphere due to their proximity to the coast. In other situations, connellite formed as a result of salt applied to roads in winter to melt ice. Therefore, seawater (marine spray) and salt (halite) were responsible for introducing the chlorine that enabled the formation of connellite.

3. Mineral Associations

4. Transmitted Light Microscopy

Refraction indices:  n_ω:  1.724 – 1.746      n_ε: 1.738 – 1.758                 

PLANE POLARIZED LIGHT – PPL

Color / Pleochroism: Blue, without pleochroism.

Relief: High.

Cleavage: No.

Habits: Long prismatic, acicular, capillary, crusts.

CROSSED POLARIZED LIGHT – XPL

Birefringence and Interference Colors: Maximum birefringence of 0.014, corresponding to interference colors ranging from gray and white to first-order orange; it does not reach red and blue.    

Extinction: Probably paralell.   

Elongation sign: No information available.    

Twins: No.    

Zoning: No.     

CONVERGENT LIGHT

Character: U(+)    

2V angle: No.

Alterations: No information available.       

May be confused with: Other blue secondary copper minerals.