Newbie needs help with gem stone pricing

[Silver27]

I came across some stones from Nigeria

1) rough uncut, untreated Aquarmarine(10X loupe clean), nice sea blue color

2) rough uncut, untreated beautiful amethyst, lovely deep purple color

3) rough uncut, untreated rubellite, deep pink nice color

Can someone give me an idea of what I should be paying for pieces like this per carat/


Thanks

 

[kenny]

I think telling us the carat weight of each would be helpful.
I believe larger specimens can command a higher per carat price.

 

[Michael_E]

Can someone give me an idea of what I should be paying for pieces like this per carat/

No. That would not be possible. The reason being that the price depends upon things like the shape of the stone, the placement and type of inclusions and any color zoning and it's placement with regard to the external features of the stone. A cutter needs to be able to judge what sort of shape, weight return and color a stone may have after it's cut and if you aren't a cutter or are one with little experience, then you will be hard pressed to tell what a piece of rough should cost even if it's in your hand. From pictures no one can give you a reliable answer.

For example, the aquamarine may have surface pitting, silk in areas or not be nearly as well colored as your picture indicates. Where will the table go? How much room is there for the pavilion? What shape would work best and in what design? Is the best shape capable of being sold, (yes, there are some shapes that are very hard to sell)? Assuming that the aqua is clean and the color shown is accurate, then the price per carat could vary from $4 per carat to $10 or $12 per carat. Poorer color, small size or bad surface topography gets the low end and better material gets the high end.

 

[Silver27]

Aquamarine: 25 Carat

Amethyst: 95 Carat

Rubellite Tourmaline: 20 Carat

 

[minousbijoux]

Hi Silver: please understand that we will not be able to help you out for all the reasons that Michael E so eloquently outlined. Your best bet is to google gemstone rough dealers, find comparable rough and use that as a basis of comparison. You will likely come to realize that facet quality rough typically looks like beautiful, clear glass (except if its an alluvial pebble in which case it will look more like sea glass).
Checkout rough2refined.com as a starting point if you want to see good quality rough.

 

[bobsiv]

While Michael_E is of course right, as someone who has done a lot of online rough shopping I am going to do the irresponsible thing here and give you my best guess about value. I have no magical powers to overcome the hurdles listed in evaluating rough from a picture, but in my opinion it's easier than evaluating cut stones from a picture; so long as I also have an accompanying description of color and clarity. Here goes:

aquamarine: ~$10/carat
amethyst: ~$2.50/carat (unless it's too dark, can't tell from the pic)
rubellite: ~$15/carat

The pictures are so bad I'm only using them for shape. If the color or clarity descriptions are off at all then these guesses would change drastically.

 

[chrono]

The pictures are so terrible that I dare not even share a ballpark figure. When evaluating rough, one needs to study the type and placement of inclusions, the shape of the rough from all angles, shine a light through it to guesstimate the final colour and more.

 

[PrecisionGem]

Those descriptions don't match what I see in the pictures at all, but then again that's pretty typical when dealing with the guys from Nigeria. What they will tell you is a nice medium blue clean aqua, will most often turn out to be a very very pale included stone. The others from the pictures look way to dark to facet, which is what I would expect them in person to be.

 

[Silver27]

Thanks for all your help! I was approached by a Nigerian miner with these gem stones and since I just started learning about coloured gemstones I wanted to get some experts opinion on how to determine pricing if I were buying them for the purpose of reselling them.