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help to identify striated green crystal from Cadjebut mine

0 votes

I have a large 9.4kg striated green calcite ? crystal from the Cadjebut mine in Western Australia, this was formed in a dry cavern 200-300m deep, I have had this specimen for around 19 years but I am unsure as to what it is exactly and have not seen any examples of large striations or the shape of this crystal, it is on a base of lead, stone, zinc, the single large crystal measures 250mm wide x 170mm high x 130mm depth and has numerous smaller crystals at the base,the colour is light to dark green with an area of clear in the middle, striations branch out in all the crystals and most are around 2-3mm deep in a v configuration up to 110mm long.alt text https://www.youtube.com/watch?v=sF39pMA933A

asked Jan 7, 2015 by John Cross (280 points)

6 Answers

0 votes

That's quite an interesting shape and cool striations. The crystal is definitely twinned. I say it looks most like calcite despite its odd shape and deep striations. May I suggest touching a drop of acid to a less-visible surface and seeing if it effervesces reacting to the acid?

answered Jan 7, 2015 by hershel (46,460 points)
0 votes

Hi Hershel, I tried a drop of hydrochloric [muriatic acid] and it fized & bubbled, does this mean that it is calcite, are the striations common or rare for this formation, I also have a larger 23kg crystal white-clear striated leaf shaped crystal on an orange coloured crystal rock formation from the same cavern, this crystal has around 1,000 crystals [to many to count] with the largest being 34 x36mm I will post a video of this one as well for peoples comments.

answered Jan 7, 2015 by John Cross (280 points)
0 votes

Yes, if it fizzled and bubbled, thats the reaction indicating it as being a carbonate, which would most likely identify it as calcite. Striations in calcite are definitely known, though the depth of the striations and color is definitely interesting. Looking forward to seeing the video post. Looks like you were also able to nicely clean and trim the crystal. How did you discover this cave?

answered Jan 9, 2015 by hershel (46,460 points)
0 votes

Hi Herchel, I worked at the Cadjebut mine but did not like going underground, so when the cavern was broken through my friend gathered these samples in a bogger, I have not cleaned the crystals or trimmed them apart from water, this is how they were found, a mistake with the green crystal was that I painted some clear lacquer on it to protect it when flying back to Perth, below is the Youtube URL for all 3 crystals. https://www.youtube.com/watch?v=AxufYJhuw8Q

answered Jan 9, 2015 by John Cross (280 points)
0 votes

Thanks for the info. These are very nice calcites. See if you are able to get more of them. Try not to spray them with laquer so that they can be in their natural state.

answered Jan 11, 2015 by hershel (46,460 points)
0 votes

Hi Hershel, thank you for the advice, unfortunately when the cavern was discovered we only had 1 trip down to collect what we wanted. In 1996, an Australian mineral dealer was given one hour by the operators to retrieve specimens from a 10 x 10 metre calcite cavity lined with marcasite, before explosives were used to destroy the site. So these are the only surviving examples left from this mine.

answered Jan 11, 2015 by John Cross (280 points)
 


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