International Conferences

One of the most well-known American Gemstones are Montana sapphires. There are four recently producing sapphire districts in Montana.   These are the Missouri River & Dry Cottonwood Creek placer mines, the Yogo underground mine, and finally the Rock Creek sapphire mine.

By far the largest producers of sapphires in Montana is the Rock Creek Sapphire mine which was discovered in 1892. Rock Creek has produced in excess of 65 tons, or over 325 Million carats, of sapphires in the last 100 years.  Potentate Mining LLC, is a privately owned company that currently owns in excess of 90% of the known sapphire producing ground at Rock Creek.

There will be a discussion of the geology of formation the location of the mining operation, the mining methods & recovery techniques.   Unlike sapphire mining operations elsewhere in the world Potentate recycles 90% of the water used in the mining process and carefully rehabilitates all disturbed mining areas that have been previously worked.

Approximately 90% of the sapphires produced around the world are likely to be heat treated.  Rock Creek Sapphires are no exception to this and the heat treating methods will be discussed showing the transition to improved clarity and colors.

There will be brief discussion of why the Rock Creek Sapphire are so popular with the gemstone cutters and lapidaries around the globe due to their unique crystal form that provides good cutting yields and a range of unique colors.

Without the use of the microscope, gemology as we know it today would not be the same.  We owe our collective understanding of inclusions in gemstones to the practice of microscopy and various lighting techniques.  Pioneers such as Edward Gubelin and John Koivula have paved the way for us to continue building upon our knowledge of inclusions for the purposes of gemstone identification.

In particular, the art-science of photomicrography has become the vessel with which we all get to experience the inner world of gems. This presentation will focus on inclusions as clues to natural color origins of gems, as well those that are altered by treatments or are proof of synthetic origin and imitation.   Join me on a photographic journey through the microcosms of blue gems and diamonds!

Traceability is gaining widespread attention due to U.S. sanctions and the increasing interest from retailers aiming to strengthen the narrative around natural diamonds through transparent sourcing. See how the Diamond Journey process traces a diamond’s path from mine to market by capturing and storing data at each step, creating a verifiable record.

Artificial intelligence is playing an increasingly significant role in diamond grading, revolutionizing traditional methods with enhanced precision and consistency. Learn how the systems were developed to evaluate various characteristics of diamonds, reducing human error and subjectivity in the grading process.

The diamond industry has experienced significant transformations over the past five years. GCAL will share the trends observed in their labs, including what’s new and emerging in the market.

His presentation will include all subjects about turquoise including how to appraise, grade and give current values to turquoise and its many imitations. Storytelling is one of Joe Dan’s favorite education tools to be inclusive and honorable to all cultures and industry peoples, including the artists, scientists, collectors, and appraisers.

1. Turquoise is the most colorful gemstone in the history of the world.
2. Turquoise is rarer than diamonds when contemplating the difference between rarity verses commerce
3. Understanding that the study of turquoise is greater than science.
4. The published theories of fingerprinting turquoise sources continue to harm archeologists and scientist’s reputations.
5. The true art of imitating turquoise.
6. The Turquoise Grading System article published in the New York Times promises to quantify turquoise grading for the first time in history.

Among the “big three” (ruby, sapphire, emerald), the origin determination of sapphire is probably the most challenging task of gemological laboratories. This is because from the same region, sapphires can have different inclusions and a variation of chemical compositions, but also because in recent years, more and more deposits are discovered, and overlaps are increasing.

The lecture will concentrate mainly on microscopic properties of sapphires from various origins and their relationship to their geological environment. Covered are sapphires from Burma, Kashmir, Sri Lanka, Madagascar, and the basaltic deposits in Thailand/Cambodia and Australia. Other deposits are mentioned but not dealt with in detail. The lecture will also cover additional advanced methods to help with the origin determination, such as UV-Vis spectroscopy, FTIR, EDXRF, and LA ICP MS analysis.

Indistinguishable to the trained eye, lab-grown diamonds have caught the consumer’s attention, fueling meteoric growth over the past several years.

Along with this recent popularity come many challenges. Laboratories frequently report on undisclosed lab-grown diamonds and record-breaking sizes. Similarly, national mainstream and industry media covered numerous stories of undisclosed lab-grown diamonds.

These reports demonstrate the increased prevalence and, thus, the need to screen every stone for origin identification.

This presentation will cover the common screening technologies used for separation and, more importantly, each technique’s limitations and blind spots, as determined from Stuller’s multi-million screening tests experience.

In addition, some rare and interesting cases uncovered by the Stuller Gemological Laboratory and current research projects will be presented.

“A historical review of lab grown diamonds and their detection, including latest CVD production, treatments and cutting in India”
Branko Deljanin, B.Sc., GG, FGA, DGA, DUG, GRI Inc

This presentation will give an overview of screening and identification instruments over the past 25 years when colorless laboratory grown diamonds (LGD) were rare, up to now, with an industry-wide shift towards LGD. China is a major producer of HPHT-grown diamonds while India is a major producer of CVD-grown diamonds, the country also hosting many processing and cutting centers for LGD and natural diamonds.

During a recent visit to Surat (India), the speaker had a chance to visit CVD factories, seeing large clusters of crystals and collecting samples of as-grown, HPHT-treated and LPHT-treated CVD diamond for research and education. The cost of growing, cutting and processing CVD diamonds hit record low $90/ct and the low price is resulting in closure of CVD factories in USA and Israel, and affecting pricing of natural diamonds.

There are over 70 instruments on the market, so diamond trade is confused on proper use and interpretation of results.

It is strongly recommended to test each diamond in question with minimum 3 instruments, as there is no single instrument from any of 4 groups (standard instruments, UV transparency, luminescence and advanced spectroscopy) that could give all the time 100% ID of diamond in question.

This workshop is designed for jewelers and appraisers. You will learn about diamond types and how to identify HPHT-grown diamonds with portable instruments. You will also learn how to spot “pattern” in CVD-grown diamonds using cross-polarised filters & UV lamp and identify stone or sometimes send it to an advanced lab for further testing. Treated HPHT-grown and colorless CVD could be screened using PL/Jewelry inspectors.

 

1. Types of natural and synthetic diamonds
2. Producers of synthetic diamonds, new developments in India
3. Causes of color in natural and synthetic diamonds
4. Screening and ID of diamonds for synthetic origin

– Using Loupe (or Microscope) with portable Polarioscope (or CPF)

– Using portable UV lamp (PL /Jewellery inspectors)

1. Problems and solution in testing mounted and melee synthetic diamonds
2. Post treatments of HPHT-grown (irradiation) and CVD-grown diamonds (HPHT)

PRACTICAL LAB SESSION

• 50 samples of type Ia, IIa, IIb, Ib diamonds (natural and laboratory-grown, loose and mounted, colourless and coloured) to use with loupe, portable polarioscopes mounted on microscopes and PL/Jewellery inspectors, EXA PL spectrometer.

Things to bring home: handouts, Certificate of completion.

The goal of the workshop is to fascinate everyone about turquoise. In an open format with questions welcomed, Joe Dan will teach all things turquoise. The history and culture of turquoise are important but are only briefly discussed. The science of turquoise, it’s current availability, the imitations and how to grade and appraise a turquoise will be the focus subjects.

The power point is effective but the greatest part of the workshop is the hands-on learning about rarity, to grading, appraising, and the imitations with examples from around the world. Participants will be able to grade turquoise and even try to learn how to identify some of the imitations on the market. A question-and-answer session will also be a part of the presentation. Turquoise has a bright future for everyone in this colorful industry.

The workshop concentrates on the microscopic possibilities to detect heat treatment in sapphires, as well as typical inclusions of sapphires from various origins. The presentation that goes with the workshop also shows other means for the detection of treatments and origins, such as UV fluorescence, UV-Vis spectroscopy, and FTIR spectroscopy. Overlaps are shown, and tips to avoid possible errors are given.

For the practical part, more than 50 samples of various origins and with various treatments are available, most of them accompanied by photos of typical inclusions. Some doublets and synthetic sapphires are also available for inspection. Covered are also fancy colored sapphires.

YOGO (June 11th)
Description coming soon (limited access, pending) 

MISSOURI RIVER (June 12th )
Description coming soon

ROCK CREEK (June 16^th)

POTENTATE MINING LLC + YELLOWSTONE NATIONAL PARK

June 16 Monday, Full Day Tour MINE WORKINGS & SITE VISIT

Limit to 20 participants

8:00am  – Depart Helena in SUV Vehicles – Drive to Philipsburg (~ 1.5 hours)

10:00  am – Arrive at Rock Creek Sapphire Mine office (20 minutes from Philipsburg)

NO CELL PHONE SERVICE OR FUEL AVAILABLE ONCE YOU DEPART PHILIPSBURG

10:00am to 11:00 am – Orientation / Maps / Sapphire Picking

• Sign In Required for Safety Protocols & Distribution of PPE
• Processing of Heavy Mineral Concentrates from the Mine Site
• SWECO mechanical separation by size of all Concentrates
• SWECO magnetics separation from Concentrates
• Sapphire concentrate drying in ovens
• Picking sapphires from Concentrates (Light Tables & Sunshine) –
• Hands On opportunity for visitors to Pick Sapphires (for Potentate)
• Sorting Sapphires by Size using RO-TAP Mechanical Sieve Shakers
• Preparing Sapphire Lots for Shipping to Acid Wash Facilities
• View Eureka Gulch – rehabilitated mining area
• Complimentary Sapphire Gifts to Visitors

11:30 am – Drive to Mine Site Location from Mine Office (20 minutes)

NOON  – Stop for Lunch Break at Sapphire Ranch

• Tea & Coffee available – Must Bring your own Box Lunch
• Kitchen Facilities available
• Washroom Facilities available

1:00 pm – Visit to the Sapphire property in the Mountains

• Visit Old Cabins Abandoned by the Sapphire miners in the 1930s
• Visit Old Sapphire Workings previously worked between 1910 and 1930
• Visit recently mined area(s) rehabilitated and seeded by Potentate Mining

3:30 pm – Visit the Current Open Pit Mining in the Meadows

(Full PPE Equipment – Helmets & Vests)

• Arrive at the adjacent plant
• Presentation of the following equipment:
  • Excavator & Haul Trucks
  • Grizzly to Remove oversize rocks
  • 40 Foot Trommel to remove oversize and sort slurry by sizes
  • Slurry pumped to Jigs by size category
  • Waste Gravel & Sand – Dewatering Tables
  • Hydro-cyclone to remove sands & fines
  • Water Clarifier to Remove Clays & suspended solid
  • Settling Ponds to Recycle Water

4:30 pm – Processing Plant Shuts down

• Trommel and Water Pumps Shut down
• Crew Mobilizes to Clean out the 10 Jigs (6 mid size, 2 oversize, and 2 undersize)
• Using Vacuums, Scoops, and buckets – Sapphire Concentrate is recovered
• Concentrates transported to Mine Office

5:30pm – Depart Mine Site and Return to scenic Philipsburg (22 miles – 20 minutes)

6:00pm – Arrive in Philipsburg and Check into Accommodation

7:00pm – Dinner at the Silver Mill or Designated Restaurant in Philipsburg

Stay in Hotel