Judging stones on the picture

[AustenNut]

I''m getting ready to purchase some topaz and am having difficulty judging the pictures.

1) When looking at a stone in the face up position, should there be any dark areas at all (which when the stone is moving would be reflecting light) or is that a sign of extinction or a window? For examples look at stones 2-4. (Though if these are windows, they appear different to me than most of the windows I''ve seen in the "native" cuts.)

2) When a light colored stone is on a dark background, if there are areas that are so clear it''s almost jelly-fish like, does that mean that there''s virtually no color there and it would be practically clear on a white background? (See pictures 5 & 6, especially 5.)

3) How much similarity would stones need to have in order to be combined in the same piece (for, say, a pendant)?

4) Based on these pictures, which stones do you think are best?

 

[ma re]

I''ll try to keep this short.

1) There should be some dark areas in a stone, but shaped like facets. If they have irregular shapes like some kind of patches, that''s extinction which means that some facet angles are not quite right and that light cannot reach that far down the stone to be reflected. Windows are another thing, stones 3 and 1 have the most obvious ones and you can always see them in the center of the stone (if there are some windows). They can be described as parts of stones that don''t properly reflect light, but not due to the extra depth, but because of too little of it. When the center of the stone is too shallow, light (due to bending it goes through upon leaving one medium and entering another) just goes through the stone cause it goes too fast for the angle in order to be reflected. Hope this explanation helps a bit.
2) That''s a tricky one, cause you really can''t know how color of a stone will act in real life. Lighter facet reflections are usually always lighter than most, and darker ones are dark, but it doesen''t have to be cause you can''t know how was the photo taken i.e. in which lighting conditions. Background also plays a role, but I''d say it''s the opposite of what you described - I think very light areas of the stone will show nicer color on a white background due to a lower contrast, but that doesen''t have to be.
3) Very good question which shows that you''ve done some good researching. Matching stones in order to use them in the same piece of jewellery can be one of the most complicated parts of creating a piece, especially if there''s a lot of stones in question. They should be as similar as possible in color (and all it''s components; hue, tone and saturation), level of brilliance, cutting style, while their shapes and cuts should be carefully thought through so that they work well together. It all depends on the desing, but if it''s something like pave work or creating a larger surface of solid color using smaller stones, matching becomes very important. It''s much easier when doing pieces where color graduates in tone from lighter to darker, but it''s still important.
4) My favorite is stone #5.

Tried to make it short, but couldn''t

 

[Jeffrey Hunt]

Hello AustenNut



Great question on which Topaz is best, I’m actually surprised no one else has chimed in on this yet. [Actually one response while I was typing this up.] In my humble opinion, from looking at the photographs, all the stones are probably identical and the only variation in the photo is lighting and distance of the camera from the stone. Number 1 might be silky but I can’t really tell from the detail, it might just be better color. The cut looks to be the same in all stones and I’m guessing that the angles are the same. Slight variations in the cutting angles will produce slightly different looks in the stone. The only way to tell with these gems is to have them in hand – in this case of comparison I guessing that even the poorest photographed stone could turn out to be the best.

A number of Pricescope members know I’ve been teaching myself gem photography for the last nine months or so, I still have much to learn. My main criticism of most photos on the web is that the published photos are too small to really tell what is going on. The majority of the favorite sellers here on Pricescope are excellent cutters with the highest quality gems but for the most part viewing the smaller photos would be the same as viewing the stone in hand and arms length. Inclusions, missed meetpoints and other small problems simply will not show up. This is how I ultimately suggest viewing a stone though – at arms length. View it in direct sunlight, in shade, and even under the table (my favorite) – the same as candlelight I suppose. I do want to repeat that part about excellent craftspersons with the highest quality stones being the preferred suppliers on Pricescope! It’s true!

The problem with smaller photos on the web is that you will find an endless mass of them – think eBay – that are purposely hiding flaws with the small image. This ultimately makes it hard to tell what is going on – so the trusted gem artists are a very valuable source to return to.

I attempt to take large photos, with the goal to portray the gem under show room conditions, and even glossy print media. Each stone is lit and photographed individually – not in an assembly line type photo box set up. This also causes some problems – can the stone actually look this way in everyday life. With some of the photos no, with most of the photos the actually stones look better. On average I suppose my photos end up making the gems look a bit brighter than they are – just like the stone would look in a jewelry showroom with precise lighting. The advantage of my photography approach is that you will see every little thing wrong with the stone. You would be shocked at the eye clean stones that are sent back – they simply will not hold up under the increased magnification. I know this is why a few cutters have opted not to send in stones to be featured on the site.

I haven’t answered your questions point by point but I really think from the photos that you can’t tell what is really going on with the Topaz. I also hope you don’t mind me chiming in here.

Kind Regards,

Jeffrey Hunt

 

[LD]

They look incredibly similar and don''t forget you''re looking at different lighting/backgrounds so comparing is difficult. What it''s safe to say is they all look like they could match well - there''s only one that potentially is slightly darker in colour. I wouldn''t worry too much about the cut on these. If any of the sellers have two or more of the stones can you ask them to match for you?

 

[AustenNut]

Thanks for the replies so far.

What I''ve learned so far: Extinction means the cut is too deep and windows means that the cut is too shallow. Photographing gemstones is tremendously difficult and will usually show far more flaws than seen in real life (for big close-ups), and that viewing the small pict is usually better for reputable vendors. And all the stones are quite similar.

These stones are all from the same vendor (multicolour). I had contacted them last week about comparing the different stones and the possibility of them being photographed together, but have not heard back from them. Perhaps I''ll lob another message their way and I''ll hear from them soon. There are some more things I''m interested in getting and want it all to go in the same shipment.

Any other opinions on the stones or thoughts on the other questions?

 

[Barrett]

Extinction is present in ALL faceted gems to a certain degree but gets tricky with rubies and flourescence/silk which tend to cancel out extinction. Gems which are heavily included, however, tend to display much less extinction. This is because the inclusions scatter the light in random directions, covering up this effect (which results from the symmetry of the facets)

 

[chrono]

Sorry for chiming in late but I just got up this morning.

1. Yes, there should be some dark areas but it should not overtake the stone. Some facet darkness here and there of a facet or a few are there for contrast (scintillation) which is a good thing. What is shown in the pictures you attached are fine. They are not what I consider extinction. In fact, the cutting is of an acceptable level; not precision but quite nice for non-precision cutting. Extinction isn’t necessarily due to an overly deep cut, but rather from poor cutting. The same goes for windowing; it isn’t necessarily from an overly shallow cut but from the last few critical angles that are too shallow. There can be a stone with acceptable depth that shows terrible extinction and also a deep stone that has a huge window.

2. When a light coloured stone is placed on a dark background, this can help the stone appear more saturated than it really is. So of there is a clear-ish area, then yes, it will also be very light on a white background.

3. When trying to get a matched pair, I prefer to get both (or more) from the same vendor. It is practically impossible to purchase by pictures. I will ask the vendor to select the 2 that are closest in size and colour.

4. Since all are from the same vendor, I’d wait for the group picture.

There is no question that gemstone photography is difficult if one is trying to take accurate pictures. With the right tricks, a gemstone can look better than seen in real life using lighting, angles, backgrounds, etc. However, the vendors that we prefer on PS are upstanding and do not resort to such fakery.

 

[Jeffrey Hunt]

Clearly these featured vendors on Pricescope are not using fakery! Many however do make use of different lighting angles, backgrounds, depth of field and other photography techniques to show the gemstone to advantage. Kudos to all of them!

http://com.pricescope.com/photos/leon_mege/default.aspx

http://com.pricescope.com/photos/whiteflash/category1093.aspx Be sure to check out the lighting angles and backgrounds here.

http://com.pricescope.com/photos/wink_jones/category1064.aspx

http://www.burmarubies.com/Peridot22.html

http://www.rwwise.com/products/gallery|3

http://www.whitesgems.com/cutgems1.htm Superior use of lighting and backgrounds to show off the gem to advantage.

http://www.zavagems.com/mastercuts.htm Wide variety of backgrounds and lighting



There are many websites and vendors across the web with great photos showing gemstones to advantage. I don’t think it is fair to call the following photography fakery either. There are a multitude of examples.

http://www.bespoke-gems.com/SacredGeometrics_MainFoyer.php

http://www.gordonaatlo.com/gallery/

http://www.artofplatinum.com/4images/categories.php?cat_id=3

http://www.marinmineral.com/mixed295.html Mineral samples but excellent photography showing inclusions and the surface of the specimens in detail

 

[PrecisionGem]

Jeff, I just had my first look at your site. The photography is excellent!!!!
Care to share you technique?

 

[Jeffrey Hunt]

Hi Gene,

Thank you for the great compliment. Your website precisiongem is wonderful and your stones absolutely killer!

And yes, I would humbly share any photography techniques that I have come up with that you may find useful.

Jeff

 

[AustenNut]

Not entirely related to the topic, but how long is an expected wait to hear back from a vendor? Particularly from one of the larger stone companies rather than the precision cutters who have a smaller amount of listed stock? More than a week and a half ago I contacted Multicolour about some of these topazes, and then I sent them another e-mail on Sunday. I even let them know that there were other stones I wanted to purchase but was waiting to hear back from them so that I could combine the shipping. Do companies not respond if the stone isn''t worth at least a couple of hundred dollars?

Frankly, I''m getting rather peeved about the lack of communication, but maybe the pricepoint of the stones I''m looking at isn''t sufficient for them to bother replying. It does make me much less likely to buy anything from them though, ever.

 

[chrono]

Austen,
I usually get a response within days unless I know the vendor is out on the road. However, MC is a large outfit and as such, should have someone in the office who ought to be able to answer your questions, even to say that they are too busy to take extra pictures for you, if unwilling to do so. My suspicion is that the price point of the topazes isn’t worth the time and effort of the photography. I’m not saying whether that is right or wrong, but their profit margins on those are pretty slim to begin with.