Gem News International Gems & Gemology, Spring 2014, Vol. 50, No. 1

Gem Crystals – Tucson 2014


カルサイト(方解石)結晶がついたタンザナイトの結晶
Figure 1. Tiny calcite crystals adhering to the surfaces of this superb tanzanite crystal, along with the brown coloration around its base, are strong indicators that the material has not been heated. The crystal weighs 500.45 ct and measures approximately 8 cm in length. Photo by Eric Welch; courtesy of New Era Gems.
At the Pueblo Show, Steve Ulatowski (New Era Gems, Grass Valley, California) told us how the dynamics of his business have shifted from facet-quality rough to crystal specimens, which now make up more than 80% of his turnover by dollar value. In particular, small gem crystals in wire-wrapped jewelry now form a large part of his commerce.

Steve Ulatowski
New Era Gems
Gem-trade veteran Steve Ulatowski describes the recent market changes have driven prices for rough colored gems of all types to unprecedented heights. He explains the impact on his business and reveals some of the key factors behind these momentous market dynamics.
Ten years ago, facet rough made up 90% of New Era’s business, while gem crystals were a mere 5%. Facet rough now represents just 10% of his total, because it is nearly unobtainable.

As an example of changing market dynamics, Ulatowski showed us a fine tanzanite crystal (figure 1), which previously would have been more valuable as a mineral specimen. In today’s frenzied market, such a crystal might be worth $45,000 uncut but command $50,000 as rough for faceting.

According to Ulatowski, the criteria for a superior gem crystal include luster, color, and the condition of its edges (absence of nicks or chips). Whether or not it has a perfect termination also plays a role. Another consideration is the potential amount of cuttable material. For example, a 109- gram tanzanite crystal might yield 80 grams (400 carats) of cutting material, which would yield on average about 160 carats of fashioned gems.

Ulatowski noted that due to demand for cutting rough in late 2013, many crystals were broken for that purpose. Fine, well-formed crystals once commanded a premium over those suitable only for cutting fashioned gems; a fine crystal might be worth twice as much if left as a specimen. Although fine crystals are exceptionally rare, the market for cutting rough is tremendous right now, with worldwide shortage of every type of cutting material—even staples like blue topaz and smoky quartz. He has never seen a rough shortage comparable to this current one. Like other dealers at the shows, Ulatowski believes this represents a combination of less global mining activity, stricter mining regulations in many countries, rising fuel costs, and growing Asian demand.

Still, his U.S. client base is reluctant to pay higher prices for what they perceive as overpriced rough. There is also a growing trend toward better cutting at the source, with governments trying to support their own domestic cutting industries, as this retains more value in country than merely exporting the rough as raw material.

Tanzanite crystal
Figure 2. This 335.46 ct crystal contains relatively little cuttable material, but its crystal form and condition are excellent, making it worth five times more as an uncut specimen. The cuttable portion is located near the tip of the crystal, where the rough begins to narrow, so there is not enough depth for a significant faceted stone. Photo by Eric Welch; courtesy of New Era Gems.
Ulatowski had a range of unheated tanzanite crystals, which he estimated might make up 20% of total rough tanzanite production. He showed us many examples with blue to green terminations and brown coloration near the base (figure 2). A few blue crystals included calcite matrix, while some had associated pyrite.

Although many in the trade say all blue tanzanites have been heated, Ulatowski explained that it is impossible to heat only part of a crystal. Therefore, any crystal that is brown on the base has not been heated. In many specimens, the brown base is best for cutting, as it is usually the widest part of the crystal.

Demand for what Ulatowski calls “fancy tanzanite” (zoisite) is strong, with top pink colors selling for up to $800 per carat. Unheated natural pinks usually form only in the tip of the crystal, so most stones are small (less than a carat). The most valuable specimens are pure pink, with no purple cast.

Heated tanzanite crystal
Figure 3. This 765.00 ct tanzanite crystal was heated in an oven at approximately 1000°F to remove all brown coloration. After the temperature was raised incrementally over a number of hours, the peak temperature was maintained for one hour before gradual cooling over a period of six to eight hours. Prior to heating, the crystal was completely brown, with no traces of blue. Photo by Eric Welch.
For contrast, Ulatowski showed us a heated crystal where the brown coloration had been removed (figure 3), as well as a natural unheated reddish brown sample (figure 4) with no hint of blue. He also had a range of green grossular garnet crystals, a byproduct of Merelani tanzanite mining (figure 5). Also remarkable were bicolor tourmaline crystals (figure 6) with an unusual etched core but intact terminations. These were reportedly from the Barra de Salinas mine in Minas Gerais, Brazil.

Reddish brown zoisite crystal
Figure 4. Specimen crystals, such as this 87.59 ct natural-color unheated reddish brown zoisite, are currently the mainstay of Steve Ulatowski’s business. Photo by Eric Welch; courtesy of New Era Gems.
In closing, Ulatowski noted that his best sales year at Tucson was 2013, but that 2014 was headed in the same direction.

Green grossular garnet crystals
Figure 5. In Merelani, green grossular garnet (tsavorite or “mint” garnet) is a byproduct of tanzanite mining. This unusual 27 ct group of intact euhedral crystals measures approximately 4 cm in length. It is a “floater,” meaning there is no visible attachment to any host rock. Photo by Eric Welch; courtesy of New Era Gems.
Bicolor tourmaline crystals
Figure 6. These bicolor tourmaline crystals are reportedly from the Barra de Salinas mine near Coronel Murta in Minas Gerais, Brazil (left). Each 2–3 cm crystal had a heavily etched, almost skeletal pink core topped by a euhedral or very slightly etched green cap. The terminations (right) may have projected into a layer of clay minerals during formation, protecting them from etching. Photos by Eric Welch; courtesy of New Era Gems.

Duncan Pay is editor-in-chief of Gems & Gemology.