Panning For Sapphires: Choosing The Right Pan

Sapphires are mostly made of the mineral corundum, which is mixed with small doses of other elements to create almost every colour of the rainbow. When panning for sapphires, you'll need a prospecting pan, two sieves with coarse and finer mesh sizes, a shovel, a bucket, and a jar to put your finds in. You can also buy gold panning kits, which include a pan, paydirt, panning instructions, a vial, a pipette, and tweezers.

What equipment do I need to pan for sapphires?

To pan for sapphires, you will need to find a location that is prospective for sapphire deposits. Once you have selected a spot, you will need to bring the proper gear, including gum boots, hip waiters, and extra clothing for cold and wet conditions. For the actual sapphire hunting, you will need a large prospecting pan, two sieves with coarse and finer mesh sizes, a shovel, a bucket, and a jar to put any sapphires in. You may also want tweezers and a magnifying glass to help you find and identify sapphires.

Sapphires are a variety of the mineral corundum, composed of aluminium and oxygen. They are very hard and can appear in a range of colours, including blues, greens, yellows, golds, and reds. The presence of different elements, such as iron and titanium, creates the different colours.

Sapphire-bearing rocks, such as massive basalt, have been eroded by rivers and streams, and the sapphires have been transported and concentrated into river deposits (alluvial beds). These deposits are found in stream banks and gravels, which is why panning for sapphires involves shovelling and sifting through river or stream sediment.

Where can I go to pan for sapphires?

If you're interested in panning for sapphires, there are several places you can go. Here are some options:

Montana, USA

Montana is known for having some of the best sapphires in the world and is the only source of sapphire mining in the United States. The majority of sapphire finds in Montana can be attributed to four major locales: Yogo Gulch, Rock Creek, Dry Cottonwood Creek, and the gravel bars along the Missouri River northeast of Helena.

Montana has several pay-to-dig operations where you can sift through pay dirt known to contain sapphires and other gems. Here are some specific places you can go in Montana:

• Gem Mountain Sapphire Mine: Located in the Sapphire Mountains, about 22 miles west of Philipsburg. This mine is one of the largest, oldest, and best sapphire mines in the world and has been in operation for over 130 years. They provide all the equipment you need and also offer a "Box of Rocks" that can be mailed to you if you can't visit in person.
• Yogo Gulch: Located in Judith Basin County, about 12 miles southwest of Utica. This area is known for its high-quality sapphires, but most of the land has been claimed for decades, so you'll likely need to find someone with mineral rights who will let you work on their land.
• Sapphire Studio: Located near Missoula, this site offers sapphire pay dirt for prospectors and has a shop in Hamilton. Reservations are required if you plan to do your washing on-site during the summer months.
• Montana Gems of Philipsburg, Sapphire Gallery, and Gem Mountain Sapphire: These stores in Philipsburg offer the opportunity to pan for sapphires year-round using gravel brought in from other locations.

Tasmania, Australia

Tasmania, specifically the Northeast region, is known for its mineral deposits, including gemstones. The rivers and streams in this area have eroded sapphire-bearing rocks such as massive basalt.

To get started, you'll need to find a prospective location. The Mineral Resources Tasmania pamphlet can provide more information on potential areas: http://www.mrt.tas.gov.au/portal/en/fossicking-areas-in-tasmania. Once you've selected a spot, make sure to bring the proper gear, including gum boots, hip waders, and extra clothing for cold and wet conditions. You'll also need a large prospecting pan, two sieves with different mesh sizes, a shovel, a bucket, and a jar for any sapphires you find.

What is a sapphire made of?

Sapphires are a variety of the mineral corundum, which is a form of aluminium oxide (α-Al2O3). They are typically blue, but can also be found in shades of yellow, purple, orange, green, black, pink, violet, grey, and even colourless.

The variety of colours sapphires appear in is due to the presence of certain metals or impurities in the mineral during its formation. For example, sapphires that have been coloured by iron and titanium will be blue, while chromium is responsible for pink sapphires, and iron alone produces yellow sapphires.

Sapphires are found in recrystallised limestone and metamorphic rocks with low levels of silica and high levels of aluminium. They are formed when transition metal minerals seep into the crystal lattice of the sapphire as it forms, transforming its colour from white and transparent to a different hue. The rate at which the surrounding magma cools also affects the size of the sapphires, as the larger crystals have more time to form.

Sapphires are the third hardest mineral, measuring 9 on the Mohs scale, after moissanite and diamonds. Their remarkable hardness, coupled with their vibrant colours, make them ideal for use in jewellery.

What colours can sapphires be?

Sapphires are available in a wide range of colours. While sapphires are generally known as blue gemstones, they can be found in almost every colour of the spectrum. The different colours of sapphires include:

• Blue: The most popular and well-known colour, blue sapphires are a constant favourite for engagement rings, earrings, and pendant necklaces.
• Pink: Pink sapphires have been growing in popularity and are considered trendy for use in engagement rings.
• Yellow: Still considered one of the most popular gemstone colours, yellow sapphires have been increasingly used in engagement rings since the early 2000s.
• White: White sapphires have become a phenomenon in recent years and are set to be even more widely coveted.
• Black: Black star sapphires have an elusive and earthy feel, providing a special look to all styles of jewellery.
• Green: Green sapphires are rare, as they are uniformly saturated in colour, and are prized by many collectors.
• Purple: Purple sapphires always have purple as the dominant colour and range from medium to dark reddish-purple with weak to vivid colour saturation.
• Orange: Orange sapphires have deep golden, mandarin, or deep orange colours.
• Colourless: Colourless sapphires, also known as leucosapphires, are another variety of the gemstone.
• Violet: Violet sapphires are also a variety of the gemstone.
• Peach: Peach sapphires are available for use in engagement rings and other jewellery.
• Bi-colour: There are also bi-colour sapphires available.

Additionally, sapphires can be classified as "fancy sapphires", which include all colours of the gemstone except blue and red (red sapphires are known as rubies). The most famous sources of sapphires are Kashmir and Myanmar (Burma), which produce sapphires of a rich colour that is slightly hazy and highly prized by connoisseurs. However, most of the beautiful sapphires today come from Sri Lanka or Madagascar, which produce a wide range of sky blue stones or gems with rich, saturated colours.

How do I identify a sapphire?

To identify a sapphire, you can look out for several key characteristics and use certain tools. Here are some ways to help you identify a sapphire:

Visual Examination

Sapphires exhibit irregular shapes, reflecting their natural crystalline structures. They often resemble uncut crystals or rocky fragments, with hexagonal or barrel shapes. The texture of sapphires can vary, ranging from smooth to rough, depending on the conditions during their formation. Some sapphires may have natural surface inclusions or rugged edges.

Colour

Sapphires display a wide array of colours, including blue, yellow, pink, green, and more. Within a single sapphire, the colour may vary, exhibiting different hues or colour zoning. Blue sapphires, for example, can range from pale blue to deep royal blue. While colour is a valuable clue, it alone does not confirm authenticity.

Crystal Structure

Sapphires possess a crystalline structure that follows a trigonal pattern, with hexagonal or barrel shapes. Their surfaces can be flat or uneven.

Transparency

The transparency of sapphires varies from opaque to transparent. Highly valued sapphires are known for their transparency and good clarity.

Inclusions

Inclusions or natural imperfections are commonly found within sapphires. These can include mineral crystals, minute fractures, or colour zoning. The type, size, and location of these inclusions influence the sapphire's value and appearance.

Carat Weight

Sapphire crystals come in varying sizes, and larger crystals generally yield larger faceted gemstones. Carat weight plays a significant role in determining a sapphire's value.

Cleavage and Fracture

Sapphires possess distinct cleavage and tend to fracture along planes parallel to their crystal structure. Once cut or polished, sapphires exhibit conchoidal fractures reminiscent of glass.

Hardness

On the Mohs scale, sapphires have a hardness rating of 9, making them highly resistant to scratches and suitable for everyday wear.

Tools for Identification

• Jeweler's Loupe: This small magnifying tool allows for a close examination of the sapphire's internal features, such as inclusions and colour zoning patterns.
• Microscope: Provides higher magnification and clarity than a loupe, enabling a detailed view of both internal and external features.
• Refractometer: Measures the refractive index of a gemstone. By comparing the refractive index of the sapphire with established values for genuine sapphires, you can confirm its authenticity. The refractive index for sapphires typically ranges from 1.76 to 1.78.
• Specific Gravity Tester: Measures the density or specific gravity of a gemstone, providing further clues about its identity. By comparing the specific gravity to known values, gemologists can identify the mineral composition.
• Hardness Testing Tool: Tools like the Mohs hardness scale help determine the relative hardness of a gemstone. By testing the sapphire's resistance to scratching or being scratched by other minerals, you can assess its hardness level.
• Ceramic Streak Plate: Used to examine the streak colour of a mineral. When the sapphire is rubbed against the plate, it leaves a streak that can aid in identification.

Frequently asked questions