This guide is your first step to saving money and time by NOT GETTING RIPPED OFF. There are plenty of other very useful guides out there which will explain the general rules of both diamond buying and ebay buying, as well as how to choose a good diamond. So I won't repeat them.
This guide is specifically aimed at diamonds on ebay. I am just a buyer who has learned a few lessons the hard way, and I'd like to pass them on to you the easy way! I am not qualified diamond grader or a seller of diamonds or anything like that. I've bought alot -sent back a few, sold a few, kept a few, and would like to share what I have learned.
So you know about colour, cut, clarity, carat, certification and cost. (If not, use these guides and google searches to find out about them).
First things first. You've found the diamond of your dreams. How can you be sure?
Apart from reading the description and knowing the shipping and hidden costs, how can you be SURE you are getting what you are paying for?
COLOUR, CUT, CLARITY and CARAT are almost always in the description. So how do you know that what you see is what you get?
ASK. I have found that the best questions I can ask a seller are;
Is the picture of the actual stone? (9 times out of 10 it isn't, so assume that you aren't able to see what you are buying) Lots of sellers use stock photos because they sell so much of the same thing, it would be too time consuming for them to list individual photos, so if in doubt, ask.
Are there any 'naked eye' visible carbon spots or feathers in these diamonds? (In plain language, this means "If I look real close can I see any cooties?" If the answer is yes - DON'T BUY IT! A seller can legally sell a diamond one grade higher or lower than advertised. That means they can advertise it as an SI2 but it is really an I1. They both have carbon spots or feathers, but the difference is that an SI2 requires a 10x magnifier to see the flaws, but an I1 can be seen just by looking) Also, carbons spots are brown to black and feathers are white, so if it's an SI1-SI2 with feathers, you can expect that it will look sparkling white to the naked eye, but you'll see the flaws under a 10x magnification.
Has the diamond been digitally measured or just with a ruler? (I once measured a diamond with a ruler and it was 3.8mm(0.20ct). When I measured it digitally, it was only 3mm(0.10ct). The difference was 0.10 of a carat, which is a HUGE difference) Also, the shape of a diamond will affect it's weight. Two princess cut 1.00ct diamonds can be completely different sizes.
If you are buying a pair of diamonds, ask Are they exactly matching in size or just close to? Because two same shaped, same weight diamonds can be two different measuements, ask before you buy. The last thing you need is to buy matching diamonds that don't match!
Has this diamond been enhanced or treated in any way? Technically, cutting a diamond is treatment! But the type of treatment or enhancement you want to know about is - "Has anything been done to make the diamond look nicer than it would have if it were only cut and polished?"
Treatment is usually preformed by a type of silicone being injected into the flaws so the light bounces off them and makes it sparkle real nice. (Apparently this is called 'fracture filled treatment').
In my opinion, this is not a problem if the diamond is to be completely bezel set, because the gold will hold the siliconey stuff in (logical, right!?). I have heard of the silicone peeling away and showing off every little cootie the diamond has, but I have also heard people having them in their rings for 20 odd years and never having a problem with them.
I have also heard of heat treating a diamond, which evectively simulates what carbon would do by pressurising the diamond. These services can be bought on eBay! You send them your diamond and they send you back your diamond much prettier. I haven't had any dealings with such diamonds, so cannot give an opinion on heat treatment.
At the end of the day, if the treatment has a guarantee, find out the exact terms of the guarantee, and if you are happy with it, go for it.
COLOUR diamonds come in every colour imaginable. It's always a good idea to ask the question above Is the picture of the actual stone? If the answer is no, that's ok - but you need to ask more questions. If the stone is, say, a champagne, you need to ask "What colour champagne is this stone?" The answer should start with a C (standing for champagne) and end in a number. The higher the number, the darker the stone.
A number one way to get riped off buying online is to buy a 'pink' diamond without proof that it is genuinely pink. Also, pink diamond colours begin with a P but their numbers are in reverse to champagnes - with pinks, the lower the number, the darker the stone.
A happy medium might be to buy a pink champagne. Pinks and pink champagnes are hard to come by, especially on an auction site, simply becuase they are so rare (thus the exorbitant price).
As an example, a 0.37ct (37point) marquise cut coloured diamond VVS2 can be bought online for as little as $400. I bought one advertised as a 'peachish pink'. Actual photos were listed and I fell in love with the colour. When I got it, I took it to a jeweller to check a) if it was a genuine diamond and b) if it was as advertised. He told me yes, it's a real diamond (yay! and the most important thing to get checked!) but no, it's not a pink or pinkish diamond (dammit - knew it was too good to be true!). He too was very taken by the colour. It rated as an H-I on a normal diamond colour scale, which brought the price from $4000+ down to $2800. A big difference, but for the price and the fact that I adored the colour, a real bargain. It has a rare pink/peach tint (white diamonds normally have a yellow tint), and I had it set in rose and white gold, so it looks simply stunning. So in the end, I had a $500rrp ring which had $200rrp of small side stones (plus $400 for the stone and $500 to have it made in rose gold = $1400 total expenditure) turned into a $3500.00rrp ring, which is a saving of $2100.00.
But a genuine pink diamond the same size, cut and clarity would start at around $4,000.00 and get anywhere up to $30,000.00, if you could find one!
THE MORAL OF THE STORY? You don't want to spend $4,000.00 on a diamond you think is a bargain, and when you get it you find that it's not pink, it's 'peach', and therefore you could have bought the entire ring retail from a jeweller for less! If something appears to be an absofreakinglute bargain, ask questions, and never be afraid to ask for proof (extra photos, certification, refund policy).
Also on COLOUR, If you are purchasing multiple stones to have set together, in a trilogy ring for example, it's a good idea to buy from the same seller. An SI2 G from one seller could be slightly different to an SI2 G from another. Alternately, you could buy the centre stone as an SI2 G from one seller, and a pair of matching stone SI2 G's from a different seller. Even though there may be a slight variation between the two, it shouldn't be visible to the naked eye, unless you were trained to look for such things, and the outside two diamonds would match, so at least it would be symmetrical!
CUT As you know, there are many different shapes available, and each has it's own perfect 'cut' and ratio. Below is an easy guide for the 'perfect' ratio each shape should be. To get the ratio, divide the largest number by the smallest number. So if a marquise cut diamond is 7mmx3.5mm, 7/3.5=2. Therefore the ratio is 1:2.
Asscher, Cushion, Heart, Princess and Radiant cuts should be the same height as width (5.5mmx5.5mm) - 1:1
Radiant cut may also be the same as an Emerald and Marquise cuts, half as wide as it is long (7mmx3.5mm) - 1:2
Emerald cut may also be the same as a Pear and Oval cut, one and a half times as long as it is wide (7mmx5mm) - 1:1.5
Of course, there are huge variations on the cut ratio, as you might like a rectangle princess cut, a squarer emerald cut, or you might want an almost round pear - the choice really is yours!
CLARITY I've been told that SI3 is from the 'old way' of grading, but it is still used by many sellers today. Some sellers go from SI2 to SI3 to I1, some go straight from SI2 to I1. The reason for this is that there is quite a large amount of scope for difference between grades - after all, they are trying to categorise one of millions of little stones produced by the earth!
Most sellers online will provide colour and clarity charts in their listings so you can see what it is they refer to when 'grading' their diamonds. Also, sellers can provide 'gradings' by looking at the stone themselves, having a gemologist take a look or sending it away to an official grading company. If in doubt (or if you care), ask.
When a seller states that a stone is SI3 to I1, you can probably assume that it is very sparkly and has some visible inclusions. If you want what visually appears to be a flaw free diamond, go for SI2 or higher, colour G or higher. Stones that are above those categories are usually quite gorgeous, white to the eye and represent really good value.
CARAT As I have stated, carat refers to the diamonds weight, not it's shape or size.
One carat = 100points = one gram. So half a carat is 50points which weighs 0.50 grammes. Easy!
A 5.5mm square princess cut might weigh one gram, but a 5mm or 6mm square princess cut might also weigh one gram, depending one how deep the actual diamond is. Confusing, I know! So it is usually a good idea to factor in the measurements when shopping for a specific weight of diamond.
CERTIFICATIONS An appraisal, RRP, replacement value, certification or certificate is an indication of how much you would need to insure the item for, or how much it would cost you to purchase at an average retail store, NOT how much the item should cost you wholesale, on special or purchased privately.
If you have $1000 and you spend $1000 on a diamond 'certified' at $5000, and when you get it it's ugly, or the wrong size or not as white as 'it was described' - what do you do? You can keep it (bummer), try to resell it, or you can send it back and pay extra shipping and possibly a restocking fee IF the seller will give you a refund. The best way to avoid that is - ignore the 'valuation'. Decide how much to spend based on the description and your budget and don't buy an item based on it's appraisal, RRP, replacement value, certification or certificate.
DO NOT BUY IF THEY CHARGE A RESTOCKING FEE. Restocking fees are how dodgy sellers make their money. I bought two large matching stones plus 2 carats of small diamonds. I paid $129 for them including shipping an absolute bargain. When I recieved them, the 'matching' stones were not matching, and they weren't the stones advertised. The diamonds looked like a bag of gravel.
So I contacted the seller asking for a refund. They emailed me a return form, which I filled out. I shipped the items back within their specified timeframe. Over a month later, I still didn't have a refund or replacement, so I left negative feedback. They contacted me saying they hadn't recieved my items, so they weren't supplying a refund. Another month later, I recieved back the parcel marked "Items Undeliverable". The postman told me that it meant that either the address didn't exist or they had refused delivery. Meanwhile, they had put in a Feedback Withdrawal Request. I contacted them, telling them that if they gave me a FULL refund, I would resend the items with a delivery confirmation, so I would know for a fact if it made it to their door, plus I would withdraw my negative feedback. They agreed, so I sent the items again and withdrew my feedback. STUPID MISTAKE because they only refunded $78, and when I asked why, they informed me that it was because of the 'restocking fee'. And I couldn't even leave them negative feedback! There ARE scammers out there, which is why I have written this guide.
BEFORE BUYING, READ THE SELLERS FEEDBACK - even the positive ones. It will give you a good idea of the sellers ethic, integrity and ability to represent things as they really are. Also, negative feedback is sometimes unwarranted, and in some cases, people leave positive feedback that says something like "Item not as described but I was given a refund". Information like that is important to your decision to buy.
And lastly, Patience is a virtue. If you have in mind what you want, then watch what's on offer until you find it. DO NOT settle for anything that goes against your budget or what you want.
When looking at diamonds, in addition to the questions above, I have four rules.
1. Never buy anything with a comma in the price.
2. Never buy enhanced diamonds.
3. Never buy from a seller who doesn't have a 100% refund policy (that means the entire amount you won the auction for). They don't have to refund your shipping, but it's rather nice if they do, especially if they misquoted a size or shape. Always contact the seller asap if you aren't happy with your item. Never return an item or leave feedback without contacting the seller first. I once bought a pair of diamonds from a seller and when I got them, they didn't quite match in size. When I told him, he offered me a 10% refund to keep them or a full refund if I returned them. I kept them, got my 10% refund. The second 'pair' I bought from the same seller didn't match and I sent them back. I got a FULL refund, including my shipping cost and have bought from him repeatedly since. We both left each other positive feedback. Good sellers with good products will do the right thing by buyers.
4. Always have your item checked by a jeweller as soon as you recieve it. Nine times out of ten, you will be pleasantly surprised (and usually so are they) at how much you saved. There will be the odd occassion where the item is not what it was supposed to be. This may mean it's a created stone, not genuine, or it may not be from the mine the seller claimed. Either way, a jeweller can usually tell you a) if it's genuine and b) if you got a good deal.
My favourite stores for loose stones are mlopros, gemshake, bangkokgemmart and diamondzul because they have a fabulous range at low prices and they have really clear photos of the actual diamonds you're buying.
My next favourites are superlight.diamonds, and magnificent.diamonds (who also owns another of my favourites diamonds.4.ever). They rarely use actual photos, but their descriptions are usually spot-on so you can be assured of what you are buying.
My favourite ready-made diamond jewellery stores is diamond-deal-au.
Have fun shopping and make sure you save yourself lots of money - that way you can buy more sparkly diamonds!