What is this stone worth? Did I get a good deal?

[PrecisionGem]

Often we see someone post a picture of a stone and ask; "what is it worth", or "did I get a good deal?

These are very hard questions for people in the trade, with the stone in their hand, and almost an impossible question based on a photograph and by consumers.

Here are 6 sapphires. All the same features: weight, clarity, cut except for the color. How would you sort these by value? Assume all the stones are 3 carats, what would you estimate the price to be per carat? Assume excellent cut, and eye clean.

 

[Niel]

Can I guess that it's the same sapphire in different lighting conditions?

But to rank them maybe.....
5,2,1,3,4,6?

I never answer about price as I never have any idea

 

[marymm]

[never mind]

 

[PrecisionGem]

Can I guess that it's the same sapphire in different lighting conditions?

No different stones. These are actually images from Gem-E-Price, they are not real stones.

 

[Niel]

Can I guess that it's the same sapphire in different lighting conditions?

No different stones. These are actually images from Gem-E-Price, they are not real stones.

Yea I can tell it's computer generated image.

 

[chroman]

Ignoring hue, and sorting by the tone (vertical) and saturation (horizontal) I get something like this (its a bit hard to average over those images..):



From that I'd put 3,4,6 into the bottom half, and 1,2,5 into the top half.

I'm not sure how to order 4 and 6, but they seem below 3 due to saturation. Maybe 6>4 because of hue.

I'm also not sure how to order 2 and 5. I think PS would pick 5 on top (I would!), but the market might pick the darker tone of 2.

2,5,1,3,6,4

 

[girlyglam]

This is interesting,and it really proves to me that having the perfect stone on paper doesn't mean you have the perfect stone that sings to your heart.

I'm no where near an expert or prosumer, and I'm still learning a lot. However, from what I've picked up, I would rank them 5, 2, 1, 3, 4, 6, (which, I think, is the same order Niel posted but I swear, I ranked them in my head before reading any responses! ). BUT, I was immediately drawn to stone number 3, and assuming that all have the same weight, clarity and cut, that would be the one that I want. I love the color of it, even though I don't think think it's ideal tone/saturation for sapphires.

I think it's a fine line between getting something quality that you love and getting the stone that is perfect on paper. If my ranking about is somewhat "correct", and if I had purchased stone 3 because I love the color, I certainly may have gotten a "good deal" because it's not quite ideal in color...but I wouldn't necessarily say it was a good deal because it was under-priced. Rather, it was priced accordingly, and luckily for me, I happen to love a less than ideal color. What a stone is worth and getting a good deal are two different things...in my hypothetical situation, I would have paid what the stone is worth, but I would have gotten a good deal because the stone that sings to me is less than ideal on paper.

Of course, I'm not taking into consideration situations where someone takes a chance on a stone - say from a private seller or Ebay - and then get it in hand and realize that the stone is amazing the seller had no clue they under-priced the item. I would love to experience that situation some day!

 

[pyramid]

2 - $3050.00 per carat
1 - $2800.00 per carat
3 - $2300.00 per carat
5 - $1700.00 per carat
6 - $1500.00 per carat
4 - $1400.00 per carat

 

[pyramid]

Just guessing, but always feel the board 'experts' here recommend stones which are too light (e.g. like blue topaz depth of colour). I wonder if different parts of the world like the UK where I am would rank different. I always hear and read in gemology articles that Royal Blue is the most sought after and expensive. Most on here would recommend a Sky Blue colour and say Royal is too dark.

Very interested to here the results of cost per carat from the person in the trade/original poster.

 

[pyramid]

Maybe I am confusing saturation with tone. Just seems more people over here prefer darker tone then?

 

[PrecisionGem]

Once there are a few more responses up, I'll show the per carat price for each stone.

Pyramid, most people do confuse saturation and tone. I'll put some images of the difference up on this thread later on.

 

[swissmiss]

2 - 1 - 5 - 3 - 6 - 4 similar to pyramid.

 

[lovedogs]

My guess in order (from most to least expensive) is:

5,2,1,3,6,4. Although personally I love the color of 3, I assume it's not the priciest since it isn't the desired "royal" blue.

 

[smitcompton]

Hi

5,2,1,4,3,6 The last two stones I listed are flavored with green, which I think would make them the least valuable-$500 per carat.

I don't think these are the most expensive, but 3 carats would bring them up--so 5 =$2500.00 per carat, 2=2,000, 1= 1500.00
#4=1,000 per.

I really have no idea. Just a guess.

Annette

 

[Lovinggems]

2,5,1,3,6,4.

My personal preference 5 then 3.

 

[dk168]

I have no clue, however, I shall have a go, from most to least expensive:

2>3>1>5>6>4

Personal preference: I like 2 the most, then 1, then 5.

DK

 

[dk168]

Maybe I am confusing saturation with tone. Just seems more people over here prefer darker tone then?

Not for me.

DK

 

[Acinom]

I don't have a clue. My personal preference is stone number 3 based in this single photo. But I have learned that I can better judge blue sapphires and rubies in real life.

 

[chroman]

Maybe I am confusing saturation with tone.

There can also be a coupling between saturation and tone that might not help matters.

If we look at the spectrum of light (energy over wavelengths), we percieve colors with a narrow spectrum as more saturated than those with a wider spectrum. Lasers are a good example of this. They output all their energy over a very small range of wavelengths - the spectrum is a very narrow spike. Consequently, they're one of the most saturated things around.

Compare this with your computer monitor; If you were to look at the light spectrum of a pure blue on your monitor, it would be a fairly broad bump (like a bell curve). Comparing a laser color to a primary color on your monitor (besides likely being different hues) the laser will be considerable more saturated.

Now for gems, we mostly get color through absorbtion. White light (that has lots of energy at lots of wavelengths) enters, some wavelenths are absorbed more than others, and we're left with some fraction of the original white light spectrum (and it now looks, say, blue).

In order to look more saturated, a stone needs to absorb more of the incoming energy, resulting in a narrower spectrum.

As for tone - there is a particular range of the spectrum that accounts for our perception of tone. The more energy in that region, the lighter the tone. The less energy, the darker the tone.

Especially in blues and reds, as you increase the absorption to get increased saturation, you are decreasing the energy in the spectral region that controls tone perception. So increases in saturation usually go hand in hand with decreased tone, all other things equal.

(Green can be different as the tone region overlaps heavily with green hues, making it easier to have highly saturated greeen with lighter tones).

Hopefully thats not too confusing, though I bet having pictures would help....

 

[indigoblue]

5
2
1
3
6
4

This grouping of stones really helps me see the difference in saturation and tone.

As far as price per carat, I can't really say but will guess $2500 for my top pick down to $500.

 

[PrecisionGem]

Here is a table of Blue Sapphire, showing the difference between Tone and Saturation. Every stone in a given ROW have the same Tone, and every stone in a column have the same Saturation.

 

[PrecisionGem]

So here are the prices per carat for the various Sapphires, from Gem-e-price. These are wholesale prices based on:
Transparent stone, eye clean, Excellent cut, and heat only.



As you can see, a change in color, tone and saturation can have a rather large effect on price. Seeing 6 stones together makes it easier to discern the variations. If you only had one stone to look it, it becomes much harder.

Judging from a photo's of stones from various vendors, this task becomes impossible.

 

[chrono]

Looks like I missed the fun.

I looked at Gene's picture and did not scroll down until I decided how I would rank it; 2 and 5 would come out top, with 1 next. 3 looks a bit greenish, 4 looks a bit grayish and 6 is a combo of 3 and 4. If buying for myself, 2 would be my top choice and I don't think it is too dark. 5 is less traditional in that the tone is lighter, which I think many CSers prefer and I'd happily buy this colour too. That said, these are very expensive so I'd also be happy with more budget friendly 1. So many choices for different budgets.

 

[Niel]

Pats self on back for not technically getting it wrong.

 

[PrecisionGem]

What is interesting is how the other factors, not just the color effect the price.

I took stone 5, and changed the cut from Excellent to Poor, and the price dropped to $7000, with a Fair cut it was $8000. So a shift of $5000 just on the cut.

Here are few other changes for stone 5:

1. Cut: Poor Clarity: Slight $6750
2. Cut: Poor Clarity: Moderate $5400
3. Cut: Fair Clarity: Moderater Treatment: Heating with residues $3900
4. Cut: Excellent Clarity: Eye Clean Treatment: None $20,600

You can see pricing of these stones is a tricky business and the various factors can have a huge impact on the price. Remember these are dollars per carat, so if we from stone 5 as an unheated well cut clean stone, the wholesale price would be at 3 carats $61,800.
Compare that to the same stone, but poor cut and moderate inclusions, heated with residues: $11,700.

 

[PrecisionGem]

What is interesting is that if 4 and 6 were not sitting side by side, they look rather similar. Yet there is a $9000 difference in a 3 carat stone. Certainly trying to judge a stone from a photograph you would not be able to discern this subtle difference. Stone 2 in daylight could very much look like stone 4 in incandescent light. God only knows what it would look like in CFL light!

 

[chroman]

Or with bad white balance!

 

[aussiejamie]

Brilliant posts Precision Gem! Do you recommend subscribing to the gemeprice service?

 

[PrecisionGem]

It's a bit expensive, and unlike buying a printed copy like "The Guide", once your year is up, you longer have access. I have however used the service now for a few years. There are some stones in "The Guide" that are not on GemEprice, and vise versa, so you may find it handy to have both.

 

[PrecisionGem]

Brilliant posts Precision Gem! Do you recommend subscribing to the gemeprice service?

Those really pretty Australian multicolor sapphires you cut are not in the database. It's hard to price those stones.