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Tanzanite

Tanzanite is the blue to violet variety of the mineral zoisite, coloured by vanadium and mined only in the Merelani Hills of northern Tanzania. Nearly every stone is heated to remove a brown component, a practice the trade accepts and reports note, and the stone's single source and modest durability shape how it is bought, cut and set. Byrex Gems offers tanzanite to the jewellery trade from Toronto, filmed unedited, with prices for approved buyers and viewings by appointment.

Where to buy tanzanite in Toronto

Byrex Gems lists 6 tanzanite online today. Viewings are at our Toronto office, 27 Queen Street East, Suite 407, steps from Queen subway station, by appointment. We have supplied coloured gemstones and natural fancy colour diamonds to jewellers and designers since 1988, and welcome private clients by appointment. Prices are shown to approved trade accounts; private clients can ask us on WhatsApp, where we reply within 12 hours, or by email within 24 hours. Every stone ships insured, worldwide.

Among the tanzanite listed today: 5.716 ct Pear Tanzanite, 11.02 ct Square Cushion Tanzanite, 5.62 ct Pear Tanzanite, 2.41 ct Emerald Cut Tanzanite, 1.91 ct Round Tanzanite Close Match, 1.15 ct Round Tanzanite.

What is tanzanite and where does it come from?

Tanzanite is zoisite, a calcium aluminium silicate, in which traces of vanadium produce blue and violet. It is strongly pleochroic: a single crystal shows blue along one direction, violet along another and a brownish or burgundy colour along the third. Heating removes the brown, leaving the blue and violet, and the cutter then decides which of those two the finished stone will show from the top.

The only commercial source is a short belt of hills near Merelani, south of Arusha and within sight of Kilimanjaro. The deposit was found in 1967 and the stone was named and introduced by Tiffany & Co. in 1968, taking its name from the country. The mining area is divided into blocks that are worked by a mix of larger licensed operators and small-scale miners, and the Tanzanian government regulates the trade closely.

Colour ranges from a pale lavender blue in small stones to a deep, saturated violet blue in large ones, since the colour intensifies with the path length of light through the stone. Fine tanzanite in sizes above five carats shows a depth of blue that smaller stones cannot, which is why the stone is often cut large.

How laboratories describe tanzanite

A report identifies the stone as natural zoisite, with the trade name tanzanite given in the laboratory's own form, and describes the colour in words. Because there is only one source, origin opinions are not usually requested, and where origin is stated it is Tanzania.

Heating is the point to read. Almost all tanzanite is heated at moderate temperature to remove the brown component and reveal the blue and violet, and the process leaves no reliable trace in the stone. Laboratories therefore state, in their own wording, that heating is customary for tanzanite and is often not detectable, or report indications of heating where they can be seen. GIA, Gübelin, SSEF, GRS, Lotus and AGL each have a standard comment, and Byrex quotes the one on the report rather than paraphrasing. Unheated tanzanite exists but is unusual, and the treatment must still be disclosed to the buyer.

Coatings have been applied to pale tanzanite to deepen the colour and are detected and disclosed by laboratories. The trade terms buyers hear are mostly colour descriptions: "AAA" and similar letter grades are dealer shorthand with no laboratory standing, and "blue" versus "violet" describes which pleochroic colour the cutter chose to show.

What to check before buying a tanzanite

Decide first whether you want a blue stone or a violet one. Both are tanzanite, and the choice is made at the cutting bench: orienting the table to show the blue direction usually costs weight, because the blue axis runs across the crystal, so cutters who want to keep weight often show the violet.

Judge the colour viewed from the top under daylight-equivalent light and a warm lamp, and look at the stone from the side to see how the pleochroic colours mix. Tanzanite is usually clean, so inclusions, especially cleavage cracks, count against it and are a risk in setting.

Durability drives the setting advice. Tanzanite is 6 to 7 on the Mohs scale and has perfect cleavage, so it scratches more easily than sapphire and can split from a sharp knock. It suits pendants and earrings without reservation and rings with a protective setting and a client who will remove it for manual work. Tell the setter to avoid pressure on the girdle, never to use an ultrasonic or steam cleaner, and to keep the stone away from sudden heat. Byrex describes two stones as a pair only when the parcel paper or report says so, and otherwise as a close match.

What drives the value of a tanzanite

Saturation and tone lead. The market pays most for a deep, vivid blue or violet blue of medium-dark tone, and pays progressively less as the colour lightens toward lavender or picks up grey. Between blue and violet, pure blue has historically commanded the higher price because it is the harder orientation to cut and is compared with sapphire, but a fine violet-blue has a strong following of its own.

Size is tied to colour more closely than in most gems, because saturation increases with depth of material. Stones of five, ten and twenty carats in fine colour are the ones that show tanzanite at its best, and they carry a premium beyond simple weight. Clarity is expected; eye-visible inclusions or cleavage cracks reduce value and raise setting risk.

Cut quality matters for light return and for the choice of pleochroic colour. Treatment is assumed, so a heated report is the baseline and an unheated report adds a premium for collectors. Origin adds nothing, since there is one source.

Supply, export rules and the single-source story

Tanzanite was found in 1967 near Merelani and reached the market in 1968 through Tiffany & Co., which named it and promoted it as a new gem available from one place on earth. That promotion, and the stone's colour, made it one of the most commercially successful gem introductions of the twentieth century, and it was added to the list of December birthstones in 2002.

The mining area is small, divided into blocks allocated to companies and to small-scale miners, and it has been the subject of successive government measures. Tanzania has, in general terms, restricted the export of larger rough so that cutting takes place within the country, licensed dealers and exporters, and in recent years built a wall around the mining area and tightened controls to curb smuggling. These measures change from time to time, and the trade follows them because they determine how much large rough reaches cutters in Jaipur, Bangkok and elsewhere.

For buyers the single-source story cuts two ways. It gives tanzanite a rarity that marketing has used with success. It also means that supply can be interrupted by policy or by conditions at one mine, which has produced periods of shortage and of glut. Fine large tanzanite appears at auction in its own right.

Buying tanzanite from Byrex Gems

Since 1988, Byrex Gems has supplied tanzanite to the jewellery trade from Toronto. The confidence of more than seven thousand trade customers has been earned one stone at a time. Many of our tanzanite come with reports from GRS, SSEF, Gübelin, GIA and other leading laboratories, and each stone is filmed in our office, exactly as it is.

Approved trade buyers see prices online. Everyone else is welcome to write: WhatsApp +1 (437) 450-3786 brings a reply within hours, and an email to info@byrex.com an answer the same day, seven days a week. What is listed is a part of what we hold: more tanzanite in larger sizes and matched pairs are kept in the vault, and what we do not hold ourselves we can source through our offices worldwide. We receive clients by appointment in Toronto, Hong Kong, Bangkok and Dubai.

Tanzanite: questions buyers ask

Is all tanzanite heated before it is sold?

Almost all. Heating removes a brown component and reveals the blue and violet, and it leaves no reliable trace, so laboratories state in their own words that heating is customary for tanzanite and may not be detectable. Unheated stones exist but are unusual. The treatment must be disclosed.

What is the difference between blue and violet tanzanite?

They are the same stone cut to show different pleochroic directions. Blue is seen along one axis, violet along another. Cutting for blue usually costs weight, so cutters often show the violet. Both are tanzanite; the choice is one of taste and price.

Is tanzanite durable enough for a ring?

With care. Tanzanite is 6 to 7 on the Mohs scale and has perfect cleavage, so it can scratch and can split from a sharp knock. Use a protective setting, avoid ultrasonic and steam cleaning, and advise the client to remove the ring for manual work.

Where does tanzanite come from?

Only from the Merelani Hills near Arusha in northern Tanzania, discovered in 1967. No other commercial deposit of gem zoisite of this quality exists, which gives tanzanite its single-source rarity and makes supply sensitive to Tanzanian mining and export rules.

Which reports does Byrex supply with tanzanite?

GIA, Gübelin, SSEF, GRS, Lotus or AGL depending on the stone, identifying natural zoisite, naming tanzanite in the laboratory's form and commenting on heating. Smaller calibrated stones are often sold without individual reports.

Does Byrex supply calibrated tanzanite and layouts?

Yes. Tanzanite's steady source and consistent colour make it well suited to calibrated sizes, matched pairs and layouts. Byrex supplies from its own stock and sources parcels through its offices and partners to a specified size, shape, colour and quantity.

Does Byrex sell tanzanite to private clients?

Byrex sells to the jewellery trade and receives private clients by appointment at its Toronto office. Prices are shown only to approved trade buyers who sign in. Private clients can view stones and have a piece made through their jeweller or through Byrex.

Can I see tanzanite in Toronto?

Yes, by appointment at 27 Queen Street East, Suite 407, Toronto. Byrex shows each stone under daylight-equivalent and incandescent light, and from the side so you can see the blue and violet directions, with any laboratory report beside it.

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