GeologyRocks

Dear Zendor

 Where do these samples come from?

The first picture, 213kb size, looks like calcite. In the centre is a rhombohedral structure in white colour, caused by breaking of a crystal along its weakness planes. Calcite has three weakness planes with 120 degree angle between them. Lower down in the photo, are brown crystals that  look like "dog-tooth" spar, which are also crystals of calcite.

 The second photo, 206kb, looks like quartz.

 The third photo is A) too fuzzy and B) not close enough to see clearly, so would need a better photo.

Also it would be very useful if you put a mm or cm ruler scale against the samples before you photograph them. Scale is very important in geology.

Hope this helps!

I thought the first was calcite initially, but there are concoidal fractures.  It may be that it is a mixture of quartz and calcite.

Second picture is definitely smoky quartz crystals.

From the third picture I'd say you are in Australia.....it appears to be upside down.  Difficult to see the detail, but again I'd guess at quartz.

Quartz is silicon and oxygen - the two most abundant elements on earth and they readily combine.  However, just because they are 'commoon, it does not detract from their beauty.  In fact, quartz is a huge family.  It encompasses dozens of other names such as chalcedony, jasper, agate etc, and more commonly amethyst, rose quartz and citrine.  More correctly it should be named ' quartz variety amethyst', although the 'variety' tends to be abbreviated to 'var.'.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

John

Ha ha ha what a nice laugh I'm having. I am actually from South Africa. I didn't even realise the picture was upside down. My Appologies. As I've mentioned in my previous reply that picture 1 and 2 is the same rock and was Collected in the Orange River and the second in Magaliesbur. I will try and take some better pictures. 

Thanks a milljion for your help so far.

Regards

Zendor

Thank you very much Stromatocaster

The first and second picture is infact a picture of the same rock just from differenet sides and was collected from the Orange river, Drakensberg in Lesotho. 

The third picture is from the Magaliesberg area around Gauteng (north west) in south africa and it used to be one piece but has unfortuenately broken in to. It is also extremely brittle and small pieces keep coming of  with handling. 

Thank you for your tip. I will take some better pics and include a ruler alongside in order for you to see the scale.

Thank you yet again, Have an awesome day

Zendor

Well RSA is half up-side-down to me. Its below the equator!!!!Orange Rive is famous as a location for blue lace agate.  In fact I don't know of anywhere else it is found.

It was the first mineral I ever collected!  Jst a 'pretty stone' to me in those days.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant