How to use or interpret things on this site:

• How to buy things from us: Montana sapphires can be purchased via eBay auctions, where we use the moniker gemmarket(tm). If you don't see exactly the parcel you want, please let us know. For example, if we are auctioning 3 pink and 3 blue 2.5mm rounds and you want 4 pink and 4 blue 5x3mm pears, tell us, and within reason, we will serve it up on eBay or let you know if we can't.
• How to contact us: Every page in the site has both two links ("contact us") which will fire up your email client with our email address (sales@gemmarket.com), and a suggestion box link, which will get a message to us without using your email client (in case you are in a place -- like an internet cafe -- where you don't have access to your email client.)
• How to return things to us: This merits its own page. Go to Returns.
• How to use Montana sapphires: They tend to be small, of unusual color and often in pastel shades. They look best against white metal, and if exact uniformity is important to you, don't set them too closely together. Go to Montana Sapphire, which shows the color range and some possible combinations. Go to Hayden & Hudson, Ltd which shows some made-up jewellery.
• How to use the glossary: This is everything we have had to look up, plus words that have a specific gemmological context that might be confusing. Try looking up ametrine in dictionary.com. The glossary lives in a pop-up window which your browser or your firewall might be instructed to suppress, so you might have to change your settings to permit pop-ups for a moment.
• How to use the gemmological table (spreadsheet): This is mostly notes from the "practical" (as opposed to theory) work of the FGA program. Spreadsheets are useful for this kind of data, because you can hide and sort columns. Images, including idealized spectra, can be found respectively in the columns labelled "img" and "spectrum." To take advantage of the sorting feature, we have had to adopt naming conventions for colors, for example, that may be less than poetically-descriptive. It, too, lives in a pop-up window.
• How to use the identification strategy game: This game permits you to narrow rapidly the range of possible identifications, based on measurements that you can make (roughly) without instruments if you are experienced at handling gemstones, and more precisely with instruments. The idea is to narrow the range sufficiently so that one can then make a decisive identification with a spectroscope,for example. If you have no experience and no instruments, it is intended to give you an idea what gemmologists do.
• How to enlarge images: Every image appears in the body of a page as a thumbnail so it downloads quickly on your computer. If you want to enlarge it, click on it.
• How photographs were taken: Most were taken with a Nikon Coolpix (digital), the photomicrographs through the optics of a Nikon SMZ1500. Most inclusions are visible at 10x. Magnification rarely goes above 30x. Macrophotographs of specular subjects are usually better taken with a conventional camera, bellows and a macro lens. If the Coolpix was used for a specular subject, it is inside a light tent. Lighting is generally fiber optic at 3100K. For macro objects, a daylight filter was used to raise the color temperature. White balance settings almost always match the speedlight or were measured. Some of the photomicrographs used a fluorescent setting because it better preserved the color of the stones, at the cost of imparting a slightly greenish background on some monitors. We do not use Adobe Photoshop to alter color, but then we have no images of color change. Our monitors are set to Gamma=2.2. Sadly, the images here have to be degraded significantly in order to make them downloadable. The originals are about 1 Mb. The 600x450 pixel version displayed here may be 1/20th of that. Some more precise data on photography is available here.
• What immersion liquid is used: Benzyl benzoate is adequate most of the time, but as John Koivula points out in his excellent article "Photomicrography for Gemologists" in the spring 2003 issue of Gems & Gemology, if you develop lazy habits, you only find what you are looking for and never what may surprise you. Benzyl benzoate is a solvent for plastics, so where there is a danger of damaging a specimen -- because it is or may be organic, a composite with a layer of glue, or contain some plastic -- we use peanut oil.
• What browsers do we support: This site has been extensively tested only on Internet Explorer, and always on the latest version. Please complain if that is a problem.