Saturday, June 7, 2008
Boleite from El Boleo, Baja California
This mineral takes me back to 1975, when I took Mineralogy with Professor Raul Ortiz Asiain in the faculty of Engineering of the National Autonomous University of Mexico; he used to bring specimens to class fostering our love for minerals, and boosting the learning process of us, the students. Of course not everyone enjoyed the minerals as much as I did for instance.
I feel lucky I learned so much, and moreover when I was selected professor of the same subject, and I taught it from 1987 until 1989, the year I moved to the USA. Anyhow, I feel it was like a month ago when I saw the first crystal of boleite, its bluish color, its crystallography made a mineral simply unforgettable.
Below is boleite's technical details:
Chemical Formula: KPb26Ag9Cu24Cl62(OH)48
Potassium 0.36 % K
Copper 13.94 % Cu
Silver 8.88 % Ag
Hydrogen 0.44 % H
Lead 49.26 % Pb
Chlorine 20.10 % Cl
Oxygen 7.02 % O
Environment: Sedimentary copper deposits. The fugitive presence of K in the formula was determined by microprobe.
Locality: Boleo, Baja California, Mexico.
Name Origin: Named after is locality.
Cleavage:  Perfect,  Good
Color: Indigo blue, Light blue.
Density: 4.8 - 5.1, Average = 4.94
Diaphaniety: Transparent to sub translucent
Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit: Pseudo Cubic - Crystals show a cubic outline.
Hardness: 3-3.5 - Calcite-Copper Penny
Luster: Vitreous - Pearly
Streak: Light green
Estimated Radioactivity from Boleite: Barely detectable
I apologize I took a long break, just changed jobs from Dresser-Rand to T3 Energy, in the meantime I was busy, and traveling like a pilot. I am getting a little bit more relaxed, so thank you for your patience.
I hope you enjoy a terrific weekend, today is 6/7/08, visit my website if you have some chance: Oscar el Mexicano