Mining Madagascar

Madagascar, the 4th largest island in the world, is steeped in history dating back more than 80 million years. It wasn’t until the early 1990’s however that the gem and jewelry industry began to take notice of Madagascar as a source for gemstones.

In 1998 the first pink sapphires were discovered in Ilakaka leading the small town of only a few huts to become overrun by thousands of people seeking to strike it rich with Madagascar sapphires. The first pink sapphires led to many more, and the rush for sapphires in Madagascar continued into the 21st century with new sources of sapphires sending thousands of miners chasing the dream throughout Madagascar’s varied terrain. Madagascar is now the world’s largest producer of gem quality pink sapphires as well as blue sapphires of both exceptional color and clarity. It is estimated that Madagascar sapphires make up at least 70% of the world’s gem quality sapphire production.
With our 1300km2 of mining concessions and operations, our Mauritius based workshop and laboratory, as well as our soon to be opened offices in London and New York, with more to come.  KAT Sapphires Ltd is not only the largest producer of pink sapphires, but also a leading producer of blue and fancy colored sapphires, both heated and untreated, and available with greater ease to the trade.

Workshop Mauritius

The benefits of our Mauritius based office, workshop, and laboratory are two-fold.

First and foremost is the island’s proximity to our concessions in Madagascar resulting in a greater ease of export and sapphire traceability. Secondly, Mauritius offers our company and our clients a safe, secure, and accessible location in a Free Trade Zone.

Geology

Our sapphires are mined in the Triassic-Early
Jurassic detrital formations of the Isalo group which contain gem corundum as giant paleoplacers.

The source of these gems is thought to be the metamorphic granulitic terrains in the Precambrian basement of southern Madagascar. These paleoplacers made up of alluvial and eluvial sediments formed with the deposition of the Isalo Formation approximately 200 million years ago.

Exploration

Our mining experts utilize space age technology to target 200 million year old sapphires.
To efficiently identify the existing paleoplacer sapphire deposits we study high resolution satellite imagery and elevation data.

The SRTM regional DEM figured images identify 3 main apparent geomorphology features:

1.   Elevated, highly dissected regions identified on the project area. It is interpreted that the Isalo I sandstones have been slightly uplifted relative to the Isalo II unit.  These two areas of the Isalo I sandstones outcrop are divided by a east-southeast draining river.

2.   The ferruginous capped, flat topped hills located on the project area are outcropping Isalo II sandstones and red beds. The flat plateaux at this elevated position are interpreted to represent regional, sub-horizontal, weathered surfaces that have eroded to form the current terrain.

3.   Incised rivers and valleys with moderate relief cover the entire project. These rivers cut into and through the sequence of cover sediments and into the underlying Isalo II sandstones. The ridges between rivers are made up of cover sequence sediments with outcropping Isalo II sandstones lower in the valleys and along channels.

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Geomorphology – DEM  Digital Elevation Model

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3D Oblique View – SRTM Shuttle Radar Topographic Mission

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3D Satellite Interpretation of Prospective Sediment Horizons

Once our geologists have identified high potential sapphire deposits, our mining engineers excavate these deposits as shown in the sequence of figured images.

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Cross Section of an identified target

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The Mined target showing main gravel sapphire deposits

Sapphires – Exceptionally Rare

Sapphires are born in the great depths of the lithosphere where immense pressure (20Kbar) and temperatures (1100 C) conditions are required for them to form.  Even though, we know that sapphires have been ripped from the earth’s crust by magma rising to the surface, their origin remains uncertain.

Sapphires, along with rubies, are gemstone varieties of the mineral corundum, an aluminium oxide, Al2O3.  Depending upon trace amounts of additional elements within the aluminium oxide crystal lattice, the corundum gains its unique colour saturation.  All colours of corundum are referred to as sapphires unless the crystal has a trace impurity of chromium which can cause the stone to turn red, and thus be called a ruby.

Although blue is the most well-known colour of sapphire, many people do not know they can form in every colour of the rainbow.  Blue, yellow and pink are the most common, but green, orange, purple, brown, colourless and combinations of the colours occur as well. The rarest color of sapphire, in fact, is a beautiful combination of pink and orange that is known as the Padparadscha.

Star Sapphires and Color Change sapphires are types of corundum that are classified as phenomenal gems.  The 6, and sometimes 12, rayed stars are created by intersecting rutile inclusions inside of the stone and when light is shined on them the star appears.  A colour change in sapphires is caused by the presence of the trace element vanadium.  The most common colour change is from violetish blue in daylight to purple in incandescent light, but can occur in other combinations as well.