Hello, you lot.

I found what I suspect to be a diamond on the street last week. What a
stroke of luck!

I'm utterly inexperienced in these matters, and would like to know how
to tell whether my find really is a diamond and what to do if it is.
It's about 5-6 mm in diameter at its widest, very bright and sparkly,
and cut into an round/octagonal shape. What sort of tests can I do at
home to check that it's (more or less) authentic? Then - where can I
take it to be valued and (if possible) turned into cold hard cash? Can
I realistically hope to get a decent amount of cash for something
whose provenance etc. is untraceable?

I live in south-east London, but can of course venture into central
London. Thanks for your help - I've done a bit of poking around (I was
a GAR myself once, y'know) but would appreciate another perspective.

<Found property.
Before doing anything with the diamond, under UK law you will need to
make reasonable steps to locate the diamond’s owner.

Found property should be handed in to the police station that is
closest to where you found the item. If it is not claimed within a
certain time period it will be returned to you. For example Barnet
police station will return the property to you after 28 days if it is
not claimed.
http://www.met.police.uk/barnet/pages/calling_in.htm#found_property

According to Thames Valley Police, you may keep an item of
non-identifiable property after 14 days so long as you take reasonable
steps to locate the owner during the 14 days.
http://www.thamesvalley.police.uk/faq/default.asp?Action=Q&ID=486



How to tell a diamond is real.

There are several ways that you can get an indication of whether or
not the diamond is real.
Several sites recommend the fog method. If you breathe on the diamond,
like you breathe on a mirror to fog it over, a diamond should stay
clear.
Another test is trying to read newsprint through the back of the
diamond. If you can read the newsprint it is likely not a diamond.
Although a false result can be given if the diamond is shallow cut.
http://www.diamondcuttersintl.com/diamond_education/articles/buying_diamonds/realthing.html

It is possible to tell by the feel of the diamond. If you rub a
diamond between your fingers it should feel sharp and will not slide
very easily.
http://www.diamondtalk.com/forums/archive/1/2001/8/3/9260/How/to/tell/a/diamond/is/real/by/looking

If you can look at the stone under a microscope or other magnifying
device, check for inclusions. This is a good indication that it is a
diamond rather than a cubic zirconium.
http://www.gottrocks.com/chat-cz.htm

Real diamonds and fake diamonds.
http://www.buydiamondearrings.com/real-fake.htm

You could take the stone to a couple of local jewellers for an
indication of its value. However for a definitive value to be put on
the diamond it will need to be graded. The diamond high council (Hoge
Raad voor Diamant, HRD) in Antwerp, Belgium, grades diamonds and will
issue a certificate that guarantees the authenticity of the diamond
and describes its qualities so that the value can be determined.
Diamonds can be sent for grading by registered mail. The process takes
5 days.
http://www.diamonds.be/professional/certificate/dia_certi.htm

The price of the certificate depends on the weight of the stone. As a
guide, a certificate for  a stone between 1.00 ct and 1.50 ct will
cost about $85 (approximately £51.00)
http://www.hrdcan.com/Buying%20diamonds.htm



Selling the diamond.
Finding a trade buyer.
London’s jewellery trade is centred around Hatton Garden. A directory
listing 37 diamand cutters, polishers and merchants is given at
http://www.touchlondon.co.uk/comdir/searchresults.cfm?keyword=Diamond%20Cutters,%20Polishers%20and%20Merchants>



<Additional links:>
<A diamond education.>
<http://www.buyadiamond.net/page/4c/4c.shtml>

<Original diamonds>
<http://www.original-diamonds.com/>


<Search strategy :>

<diamonds "how to tell">
<://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=diamonds+%22how+to+tell%22>

<"diamond certificate" costs>
<://www.google.com/search?sourceid=navclient&q=%22diamond+certificate%22+costs>

<"found property" uk>
<://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=%22found+property%22+uk>

<Hope this helps.>

Thanks, belindalevez. A very thorough and useful answer. Amoral
reprobate that I am, I hadn't thought to consider the legal
implications of locating the owner! Anyway, the stone passes the fog
test and the newsprint test, and (I think) the sliding between the
fingers test. So perhaps I shall head up to Hatton Garden and try my
luck...