[Rockhounds] Selenite

[Earl R. Verbeek]

A related question, but is this specimen selenite, or just gypsum?  I'd
always understood the term "selenite" to apply only to colorless,
transparent gypsum, but at mineral shows, especially, it seems that almost
every gypsum specimen is labeled "selenite".  John White wrote a column
about the overuse of the term "selenite" in a recent (several years ago?)
column in Rocks and Minerals in his "Let's Get it Right" series, but I do
not have access to that column at the moment.  In any event, I don't
believe that fibrous to columnar crystals of gypsum of ram's horn habit
conform to any strict definition of "selenite" because you can't see
through them -- the ram's horn aggregates may be translucent, but they
aren't transparent.  What say other members of the list?

          Cheers-   Earl

On Mon, 13 Oct 2008 23:45:04 -0400,  wrote:
> John,
> 
> I think we already did vote, and rams-horn won. But I'll stuff the 
> ballot box with a another vote for Alan's "a cluster with ram's horn 
> growth habit". Vote early, and vote often.
> 
> Kreigh
> 
> 
> On Monday, Oct 13, 2008, at 22:32 America/Detroit, John Siebel wrote:
> 
>> Thanks to all for your input! Shall we vote? :-)
>> John
>>
>> it's kind of somewhere in between stalactitic and trying to be a 
>> rams-horn
>> selenite...
>> Pete
>>
>> Bovicornuate.
>> Hans
>>
>> I think "a cluster with ram's horn growth habit" is the best 
>> description.
>> Alan
>>
>> Dendritic-bladed?
>> Kreigh
>>
>> Looks like druzy curled wings.
>> Glenn
>>
>> -- 
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> 
> 
>