Whilst out fossil hunting yesterday in our local river bed my little boy came across a small (under 1cm) chunk of what looks like crystal or glass, I know there is little chance of this actually turning out to be a diamond but he is only 8 with a brilliant imagination and I promised him I would ask an expert just to make sure it is not the find of the century It was found in the river bed of the river Annick, Ayrshire, SW Scotland if it helps. I have tried my best to take macro shots using a jewellers loupe light to backlight.
Well done for looking.
Well done for noticing something interesting.
It is not a diamond, sorry!
It is probably calcite (a form of calcium carbonate), probably from a vein in the rock.
One the the things that tells me that is the chevron marks (second photo). They show what is called crystallographic twinning - which is fairly unusual.
Calcite can occur in many different forms, some of which are shown here
(search the page for 'Marchienne' and you'll see twinning a bit like yours).
Keep looking, because you never know what you might find!
Hi Mike, Thank-you for taking the time to answer, Your information is brilliant and much appreciated. Leon (My Son) will still be delighted with his find as it's "treasure" to him, along with every crinoid fragment he has found so far. Adventuring with my Son is one of my greatest joys, it's precious to feed those little curious minds
ps:Is it common to find these in Scottish river beds?
I hope little Leon's curiosity leads him to find much more treasure, in whatever form, and continues to give you so much joy in so doing. You watch him grow and beam with delight at 'specials' of the things that interest him, but you know not where it will lead him; into what and whom he might grow; on what journey he may take you both. May it be a happy and prosperous one.
I am fascinated by botany, archeology, geology and lately minerology. The amount of finds we have made in our local area is just wonderful and the real value is the learning journey it takes us on, from the initial find to hours of research and then gained knowledge, We never stop learning in this life! Thanks again Mike, I am very grateful for your knowledge and time. Donna
Just in case its something other than calcite, try Mohs Hardness test .... calcite is V Soft H=3
could e Byrite (which is soft but v heavy)
Quartz scratches glass = ie if it scratches glass then its harder than 6 and makes it way more intresting a
ie Zircon Topaz beryl etc.....
p.s. when scratching glass make sure the glass is REALLY scratched not the sample not the mineral leaving a mark (meaning its softer ) i used a window
See also minerals of scotland
|Mohs hardness||Mineral||Chemical formula||Absolute hardness||Image|
ok then its Not calcite!
Its doesnt look lke calcite as pure crystal calcite (clear calcite ) wears v fast and has v good clevage so that breaks up etc...
If it definitly scratches glass then it still could be crystalline Quartz! but it does have the chevrons found in roughdiamond l! your son is right! He sounds like me as a kid i was mad for collecting ... minerals fossills but livedin London were there a v few minerals. Gypsum, Barite, selenite, pyrite.....
There has been DIAMOND found IN SCOTLAND ?! but as far as i know they are very very small ( microscopic) Sapphire, Corundom, topaz, zircon, spinel etc...have all been found... Gold is also common if he has a gold pan or sluice ledhills have a place u can try it with all the gear... any way without further tests? try a good jeweller /gemmologist might help ?
Agreed - too hard for calcite.
Quartz is now the most-likely ID (it can show twinning).
I suggest finding yourself a piece of quartz to carry with you as part of your field equipment. You can then test specimens for hardness in the field.
You can also test this specimen - to see if it is something harder and hence more interesting than quartz.
Thanks for the further reply Mike, I should have mentioned that the specimen scratched glass. I will feel rather silly taking it in to a local jeweller to have it tested as they will think I am crazy but I will do so just for peace of mind at some point, meanwhile here are some more pictures that may spare my blushes.
It is curious how that last lot of photos make the same specimen look much more glassy - more quartz-like In those photos, I can now see some more of what looked like twinning - only now, in the new light, I think they are staggered growth lines. Those occur where you have one crystal growing against another, somewhat side-by-side, and sometimes A grows faster than B, other times vice versa.
All you wanted to know about quartz, and probably more
...Except whether your specimen is it!
Going to the jeweller...
You go ahead and feel silly if you want: they can't touch you for it!
Mike that is very true! My curiosity will take me to the jewellers sooner rather than later. That`s if I can figure out the code for Leon`s safe! It`s been a great learning journey so far and all from one shiny little "gem" found by my mini adventurer. I took these pictures in a more natural light this time Mike.
Hi Mike, I have been doing my research thanks to the pdf link you pointed out and I can tell you this about the geology of the exact find spot: If it narrows things down any?
1:50 000 scale bedrock geology description: Unnamed Igneous Intrusion Of Unknown Age - Microgabbro. Igneous Bedrock formed approximately NaN to NaN million years ago in the Period. Local environment previously dominated by intrusions of silica-poor magma.
Setting: intrusions of silica-poor magma. These rocks were formed from silica-poor magma intruded into the Earth's crust. It cooled to form intrusions ranging from large, coarse-crystalline, often gabbroic, plutons at depth to smaller, fine to medium crystalline, often basaltic dykes and sills.
I will pop by the jewellers in the next few days to put my mind at peace, just incase
Well that is useful to know, only in a stream bed in Scotland, there is always a good chance a stone will have been imported from a different geological terrain through being washed downstream and/or brought into the area by glaciation.
Keep us posted.
Thanks Mike, I will update you when I have been to see the jeweller Finding myself obsessed with geology at the moment. The museum did not need the sep nodule so I decided to crack it open to see what, if anything was inside, some dull red/purple material and a vein of clear crystal structure of some sort.
Interesting. I note the parallel-sided veins at left and bottom of top photo - almost strangely consistent in width...
But the clear crystal vein (probably quartz) is more in-keeping with septarian nodule.
If you get much more into geology, you might want to consider getting access to a rock saw and grinding/polishing machine. You'll see a lot more in sawn and polished surfaces. (Varnished is cheaper and quicker than polished, but not as high a quality.) If there is a local geology club, they might have such equipment.
Hi Mike, I will look into local geology clubs when I get the chance. I took the "diamond" to two jewellers today, In the first shop was tested by an assistant who clearly didn`t know how to read the testing probe, it lit up 3 red lights but did not beep and she said she thought this meant it was a diamond but was not sure and asked if I could return when the manager was back in a few hours, the second shop with a more experienced jeweller had a look at it and said "some type of rock Crystal".