Galena: Difference between revisions

Latest revision as of 10:13, 1 July 2026

A curve trace of galena from Ale & Cakes Mine, Gwennap. Note that the polarity is inverted.

Lustre:Metallic, Sub-Metallic, Dull
Transparency:Opaque
Colour:Lead-grey
Streak:Lead-grey
Hardness:2½ on Mohs scale
Tenacity:Brittle
Cleavage:Perfect {001}
Parting:{111}
Fracture:Sub-Conchoidal

The "OG" semiconducting mineral from the early days of radio, galena was chosen as it was the best material for converting radio frequencies into audible signals, by removing the lower half of the modulation. Often combined with silver cat's whisker contacts. Silver bearing (argentiferous) galena was said to be the best form.

Has a higher overall resistance than the pyrites and seems to gradually lose it's properties as it becomes tarnished. Different point contacts on the same specimen seem to provide reversed junctions, as in the plot above. This is much less common with other minerals. From my experience it doesn't off much better properties than, for example chalcopyrite but this may be down to the tiny signals used in crystal radios.

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+[[File:Galena.jpg|thumb|right|frame|Galena from Wheal Lovelace, Gwennap]]
 [[File:Galena-ale-cakes.png|right|frame|A curve trace of galena from Ale & Cakes Mine, Gwennap. Note that the polarity is inverted.]]
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 * Fracture:Sub-Conchoidal
-[https://www.mindat.org/min-1641.html Data from mindat.org]
+[https://www.mindat.org Data from mindat.org]
 The "OG" semiconducting mineral from the [[Semiconductor history|early days of radio]], galena was chosen as it was the best material for converting radio frequencies into audible signals, by removing the lower half of the modulation. Often combined with silver cat's whisker contacts. Silver bearing (argentiferous) galena was said to be the best form.
-Has a higher overall resistance than the [[pyrite|pyrites]] and seems to gradually lose it's properties as it becomes tarnished. Different point contacts on the same specimen seem to provide reversed junctions, as in the plot above. This is much less common with other minerals.
+Has a higher overall resistance than the [[pyrite|pyrites]] and seems to gradually lose it's properties as it becomes tarnished. Different point contacts on the same specimen seem to provide reversed junctions, as in the plot above. This is much less common with other minerals. From my experience it doesn't off much better properties than, for example [[chalcopyrite]] but this may be down to the tiny signals used in crystal radios.
+===Pages mentioning galena===
+{{Special:WhatLinksHere/Galena}}