Joined: Thu Feb 22, 2007 10:23 am Posts: 923 Location: NYC
raygem wrote:
Hi Farshid They are Sandawana emeralds from Zimbabwe.
from its blueish green color i also thought Zim.
raygem wrote:
Just had a thought.Wouldn't treating oiled emerald with NaOH get the oil out?The NaOH should saponify the oil to soap which would then wash out.
effective de-oiling process is done with solvent and special equipment for pressure and heat to get the oil out of fissures and fractures. depending to oil/resin type the solvent varies. there is simply no guide for it. its more like experimental process. but for now all you can do is soaking your materials in different solvents
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Just had a brainwave[or maybe a brainfart-I am sure you guys will let me know!!!]. I know it is dangerous to get acetone anywhere close to a naked flame,so you don't need to warn me about this. What I suggest is putting emeralds in acetone in a jar with a hermetic lid in a double boiler on an electric hob i.e. no naked flame. Heat the contents to +/- 100C,remove from double boiler and screw on the lid. The acetone will be hot[more effective] and,as it cools down,it will create a vacuum in the jar[more effective].This process can be repeated a few times to make sure any oil is removed. This process should be similar to the Soxhlet[spelling?] method to measure fat/oil in food products,with the added advantage of the vacuum. Admittedly,the Soxhlet method uses continuous recycling of the solvent to remove the oil, but the principle should be the same,except for the added benefit of the vacuum.
For your added interest.if any,my surname is Priestley and Joseph Priestley is known as the "Father of Chemistry".He discovered oxygen and Marsh Gas[but we don't talk about that much!!!]. When I was a student,I did a training job in Calne.Wiltshire and that was where he discovered Marsh Gas in a foul-smelling pond that has a statue of him in the middle.No autographs,please!!!!!
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Hi Toptan No colour change.If anything,the stones are brighter, proably because they are cleaner.In any event,the temperature would only have been around 100C and very few[if any] gems would give a noticeable colour change at such low temperature. I hope I understood your question correctly.If not,do a re-post and I will try again.
Users browsing this forum: No registered users and 27 guests
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum