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    minershop - Fluorescent Minerals from Greenland and the World

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Greenland Gemstones

Tugtupite

cab1.jpg"For ages, the Inuit of Greenland have  understood the power of tugtupite. Legend has it that lovers can cause the stone to glow fiery red just from the heat of their romance. The brilliance  and vibrant colors announce the intensity of their love."

Tugtupite was discovered in 1957 close to the town of Narsaq and to-date has only been found in two other areas - Mt. St. Hilaire (Canada) and the Kola Peninsula (Russia).  Tugtupite at Kvanefjeld is scattered in irregular hydrothermal veins up to 50cm wide.  Only tugtupite from Greenland is deeply colored and valued as a gemstone.

Nuummite

nuummite-cabochons_1.jpgNuummite is a gemstone formed from a mixture of two minerals from the orthoamphibole group: anthophyllite and gedrite.  The name nuummite is derived from the Municipality of Nuuk, where the stone was discovered in 1982.  It has since been found in several localities in the outer part of the Godthabsfjord near Nuuk.

Geologically speaking, nuummite is of volcanic origin and was formed about 3 billion years ago.  Subsequent influences on the rock (metamorphism) have given rise to the striking mixture of crystals which gives nuummite its unique appearance.  Rocks resembling nuummite are also found in a few minor occurrences in the USA, but it is only in the Greenland type that coloration is developed well enough for the stone to be suitable for gemstones.

Composition

In nuummite, the two orthoamphibole, anthophyllite (Mg,Fe)7Si8O22(OH)2 and gedrite (Mg,Fe)5Al2(Al,Si)8O22(OH)2, both with a hardness of 5 to 5.6, constitute a mixture of elongated crystals, often in sheaf-like groups.  In the transition between the individual crystals (and especially the thin ones), an optical effect is created causing a special "inner" golden brown glow.  This effect is also called iridescence, and is especially distinct on polished surfaces.  The result is that the crystals appear as bright lamellae, almost like flames in a fire.  The colors vary somewhat between reddish, greenish, and bluish hues, sometimes even within the same lamella.  Between the bright lamellae, the color is dark brown to black.

Gemstone

Nuummite is generally easy to polish, even though, in certain qualities of stones with many parallel crystals, it can be difficult to avoid holes and cracks.  The usual shape is cabochon, but other convex finishes also produce pleasing results.  In larger pieces it is possible to retain most of the colors of the iridescence, so that one end of the cabochon has a golden hue while the opposite end has a bluish tone.  Nuummite is well suited to mounting in both gold and silver.

Kakortokite

katorkit_pendant1.jpgKakortokite consists of arfvedsonite (nearly black) nepheline (off-white) syenite, containing sporadic red eudialyte grains.  It is used to make cabochons and takes a polish well.  Similar rough has been marketed as "Lopar's Blood" from Alaska.

Not a well known gem stone, it has met with great success at the Tucson show and will become another very desirable gemstone from Greenland.  Currently going through name changes due to the difficulty of pronunciation of Greenlandic names by the gem industry.

 

Greenlandite

greenlandite-rough-pendant.jpgGreenlandite was discovered in the 1960s during the survey of the large iron deposit, Isukasia north of Nuuk.  Greenlandite was subsequently discovered in several localities in the Godhabsfjord area.  It was later established that the geological environment in which greenlandite was formed was in the order of 3.8 billion years old.  this means that we are talking about one of the earths oldest formations!

Geologically speaking, the rock consist of quartzite with a large content of a green minerals - fuchsite - evenly distributed throughout, giving the stone a fresh green color.  Quartzite is made of fine-grained quartz, while the chromium-containing fuchsite resembles glitter, with fine spangles distributed throughout the rock.  Greenlandite is a hard mineral, often translucent with a metallic inner glow derived from its many spangles.  this type of stone is also known, in the jewelry trade, as aventurine quartz.

Greenlandite has been used as a gemstone in Greenland for many years, justly marketed as "the world's oldest gemstone".  Green aventurine quartz has long been known as an Indian or Brazilian gemstone, and more recently stones from southern Africa have appeared which can be difficult to distinguish from greenlandite.  Experts will note that the color of greenlandite is a more bluish green than that of the foreign variants of aventurine quartz.  Any confusion with jade (nephrite) (hardness H=6) can be resolved with a hardness test.

Composition

Greenlandites' two components are quartz (SiO2) with a hardness of H=7 and fuchsite (K(Al,Cr)2AlSi3)10(OH,F)2) with a hardness of H=2.5.  As a result the stone is very hard and can readily be polished to a smooth surface.  Varying green (fuchsite) and white (quartz) schlieren (streaks) in the same piece can produce many variants of the stone.  That indeed is part of greenlandites' singularity.

Gemstone

For lapidary purposes the most usual form is as a cabochon, but flat polishing also produces pleasing effects.  Thin slices are partially translucent, and are therefore well-suited to uses where light can shine through them.  Polished greenlandite is best suited to mounting in silver.  Superb results have been obtained by mounting in combination with other single-colored gemstones, such as red tugtupite, or blue lapis lazuli.

Greenlandite is well suited to carving for signet rings, for example.  the best-known use of greenlandite is in fact in the Bishop of Greenland's cape.  Larger pieces can be used decoratively as bookends or letter racks.  It is also well-suited for use in larger stone arrangements, mosaics, and candle holders.

Fiskenaesset Ruby

ruby1.jpgRuby crystals appear as single crystals and clusters up to several centimeters at several of the sapphirine localities in the Fiskenaesset area.  The color varies from rose-red through pigeon-blood red.   Fiskenaesset rubies have an unusually high chromium content (up to 3.0%) and are reportedly strongly fluorescent under LW UV light.

Most of the crystals are opaque but some are translucent/transparent but very rare.  This material is well suited for cabochons and the resulting piece is a wonder of colors - ranging from deep red, green, yellow, gold, white, black, and many colors in between.

The red porphryitic corundum (ruby) crystals are set in an amphibolite matrix dominated by green hornblende with minor biotite mica.  There is some accessory sphene.

This area is being commercially mined currently, and specimens are no longer available.

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