Question about larimar.

Size each
Number
Quality: AAAAA+ .... A
Slab / rough / cabbed
Treated (ew!)

Ebay has an answer for all considerations:

www.ebay.com/sch/Larimar-Pectolite/181090/i.html?_from=R40&_nkw=larimar&_sop=15

See price+shipping lowest first then price+shipping highest first
Try to pick out the ones that are bogus (clue: they're less likely to be high quality stones in the price+shipping lowest first and more likely to be low quality stones in the highest price bracket, just in case any suckers come along).

Avoid the heated / treated. That's the stuff that looks patchy.
If you buy a cab, treat it with care. If you're buying rough, then be prepared to lose some material whilst you learn its ways. Grind with a fine wheel / disk. I've shattered a couple but still not learned its ways.

Like most things, the more you buy the cheaper it is per unit, assuming comparability everywhere else.
Value depends not only on what you paid for it, the time & trouble you go through to move it from A to B in terms of improving it and the rarity. Not only how you value it, but also others. If you're selling, then particularly others, but if you value it more, keep it.

Dont larimar cabs routinely sell for $25-50?

Most of the 4 C's (of diamond grading: colour, cut, clarity and carat (weight)) apply to other stones.

As you'll know, big diamonds are generally rarer than little ones, so the price for a diamond twice as big (assuming everything else is constant) generally triples the price. Except really big diamonds which cost even more.

I don't think clarity applies to opaque stones, but take a look at ebay and you'll see different shadowing / marks that vary between unacceptable and attractive, including the characteristic 'flower' (marketing ploy). You need to price like with like stones as you would for anything else.

You don't go to a real-estate (UK: estate agent's) and determind the average price of a house? You'd bracket similar properties and then consider those comparable. The same with stones; and double check you don't need to get 1.5 tonnes delivered from China to achieve the $/carat you're looking for. Unless you want 1.5 tonnes...

BTW, the use of carats for coloured stones is a little misleading, essentially for value, look for stones with a bigger surface area / carat.

My bad, you're right. Lol

Can't rule out just good ol' eye appeal. The better it looks, the more it costs. Specifically in relation to cabbed stones.

You have to host images somewhere and post link to it. The forum doesn't support photo storage.

Here are some instructions for posting Hope the link works!

The stone has nice color, but I can't tell the pattern. Pattern will affect price, too. It's pretty small, too. 

Metalsmith,

Okay. I ...think... I understand what you have in mind if you're differentiating between faceted gems and cabochons re: surface area.

Having studied gemology and faceted a few hundred colored gems, I have a pretty clear understanding of the roles pavilion slope, critical angle, color and saturation, varying refractive indices etc. play in light return from various faceted gems. I strongly disagree that carat weight should be reserved for diamonds only however. The use of the carob seed, from which the word "carat" is derived, as a standard of gem weight goes back to antiquity. It was in use for colored gems well before the first diamonds from India made their way along the Silk Road to Rome and other points around the Mediterranean. It's standard practice for colored gem rough to be sold by the kilo or gram as rough material, and by the carat in polished goods. Varying S.G. should not be a problem as long as consumers understand that a pound of lead has much less surface area than a pound of feathers.

There are plenty of high R.I. colored gems for which light return is very important. Both rutile and anatase score higher than diamond. Sphalerite is right up there at 2.37, as are the sphene and high zircon you mentioned. And don't forget andradite garnet (var. demantoid) which is about the same R.I. as medium zircon but displays an awesome .057 dispersion (fire), higher than diamond. That's why it was named "demant" which means "diamond" in old German. Orange spessartite garnet is 1.81 R.I., same as low zircon, and it shows amazing brilliance when properly cut. In fact maximizing light return is very important in nearly all transparent gems of light hue and saturation. Even "lowly" labradorite feldspar (R.I. 1.559-1.568) can put on quite a light show when properly-cut. I just sold a gorgeous aquamarine beryl (R.I. 1.577-1.583) that has simply dazzling brilliance.

I agree that sometimes color is more important in some colored gems than light return. Emerald, ruby, blue sapphire and many others can fall into that category. But cutting for maximum brilliance is always preferable.