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Created page with "right|frame|A curve trace of calcocite from Penstruthal mine * Lustre:Metallic, Sub-Metallic * Transparency:Opaque * Colour:Blue black, gray, black, black gray, or steel gray * Streak:Blackish lead gray * Hardness:2½ - 3 on Mohs scale * Tenacity:Brittle * Cleavage:Poor/Indistinct Indistinct on (110) * Fracture:Conchoidal * Comment:Somewhat sectile [https://www.mindat.org/min-955.html Data from mindat.org] Chalcocite is also called..." |
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[[File:Chalcocite.jpg|thumb|right|frame|Chalcocite from Wheal Virgin, Gwennap]] | |||
[[File:Chalcocite-penstruthal.png|right|frame|A curve trace of calcocite from Penstruthal mine]] | [[File:Chalcocite-penstruthal.png|right|frame|A curve trace of calcocite from Penstruthal mine]] | ||
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* Comment:Somewhat sectile | * Comment:Somewhat sectile | ||
[https://www.mindat.org | [https://www.mindat.org Data from mindat.org] | ||
Chalcocite is also called "grey copper", and is an important ore of copper. It's fairly common, but tends to be more common as isolated crystals. Thick veins can be found, usually in a dense and 'massive' (finely crystallised) nature. It can look a bit like weathered sphalerite, but tends to be associated with green crusts of malachite and blue crysocolla. | Chalcocite is also called "grey copper", and is an important ore of copper. It's fairly common, but tends to be more common as isolated crystals. Thick veins can be found, usually in a dense and 'massive' (finely crystallised) nature. It can look a bit like weathered sphalerite, but tends to be associated with green crusts of malachite and blue crysocolla. | ||
It has a similarly low overall resistance as chalcopyrite - but it tends to have a very sudden and distinct point at which it starts conducting (around +1.3V), and when it does, it can carry large currents. Interestingly it can display properties of a [https://en.wikipedia.org/wiki/Shockley_diode Shockley diode], in that once 'switched on' it will remain in a conducting state until a much lower threshold (near to 0V) is reached. | It has a similarly low overall resistance as chalcopyrite - but it tends to have a very sudden and distinct point at which it starts conducting (around +1.3V), and when it does, it can carry large currents. Interestingly it can display properties of a [https://en.wikipedia.org/wiki/Shockley_diode Shockley diode], in that once 'switched on' it will remain in a conducting state until a much lower threshold (near to 0V) is reached. | ||
Due to these interesting characteristics, it tends to be a favourite of mine. | Due to these interesting characteristics, it tends to be a favourite of mine. I find it better performing than most [[galena]], easier to find junctions and less leaky - as this fairly typical curve shows, completely flat in the negative portion. It also seems to never invert as galena is prone to. | ||
===Pages mentioning chalcocite=== | |||
{{Special:WhatLinksHere/Chalcocite}} | |||
Latest revision as of 10:13, 1 July 2026
- Lustre:Metallic, Sub-Metallic
- Transparency:Opaque
- Colour:Blue black, gray, black, black gray, or steel gray
- Streak:Blackish lead gray
- Hardness:2½ - 3 on Mohs scale
- Tenacity:Brittle
- Cleavage:Poor/Indistinct Indistinct on (110)
- Fracture:Conchoidal
- Comment:Somewhat sectile
Chalcocite is also called "grey copper", and is an important ore of copper. It's fairly common, but tends to be more common as isolated crystals. Thick veins can be found, usually in a dense and 'massive' (finely crystallised) nature. It can look a bit like weathered sphalerite, but tends to be associated with green crusts of malachite and blue crysocolla.
It has a similarly low overall resistance as chalcopyrite - but it tends to have a very sudden and distinct point at which it starts conducting (around +1.3V), and when it does, it can carry large currents. Interestingly it can display properties of a Shockley diode, in that once 'switched on' it will remain in a conducting state until a much lower threshold (near to 0V) is reached.
Due to these interesting characteristics, it tends to be a favourite of mine. I find it better performing than most galena, easier to find junctions and less leaky - as this fairly typical curve shows, completely flat in the negative portion. It also seems to never invert as galena is prone to.