Name/Title
Rubellite in AlbiteEntry/Object ID
2004.1.22Description
Assemblage Zone: pegmatite dikes
Chemical Composition: Na(Li, Al)3 Al6 (Bo3) Si
Crystal System: Triclinic System
Description: Common Name: Tourmaline Var. Rubellite
Group Name:Tourmaline
Chemistry: Na(Li, Al)3 Al6 (Bo3) Si2 O18 (oh)4
Location: Jonas Mine, Minas Gerais, Brazil
Description: Large Rubellite tourmaline crystal in Albite feldspar
PHYSICAL CHARACTERISTICS:
Color Most commonly black, but can range from brown, violet, green, pink, or in a dual-colored pink and green.
Crystal habit Parallel and elongated. Acicular prisms, sometimes radiating. Massive. Scattered grains (in granite).
Crystal system Trigonal
Cleavage Indistinct
Fracture Uneven, small conchoidal, brittle
Mohs Scale hardness 7–7.5
Luster Vitreous, sometimes resinous
Streak White
Specific gravity 3.06 (+.20 -.06)[1]
Density 2.82–3.32
Polish luster Vitreous[1]
Optical properties Double refractive, uniaxial negative[1]
Refractive index n?=1.635–1.675, ne=1.610–1.650
Birefringence -0.018 to -0.040; typically about .020 but in dark stones it may reach .040[1]
Pleochroism typically moderate to strong[1]
Red Tourmaline: Definite; dark red,light red
Green Tourmaline: Strong; dark green, yellow-green
Brown Tourmaline: Definite; dark brown, light brown
Blue Tourmaline: Strong; dark blue, light blue
Dispersion .017[1]
Ultraviolet fluorescence pink stones—inert to very weak red to violet in long and short wave[1]
Absorption spectra a strong narrow band at 498nm, and almost complete absorption of red down to 640nm in blue and green stones; red and pink stones show lines at 458 and 451nm as well as a broad band in the green spectrum[1]
Fracture: Uneven, small concho
Hardness: 7 Quartz
Luster: Vitreous
Occurrence: Tourmaline is a crystal silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classed as a semi-precious stone and the gem comes in a wide variety of colors.
Tourmaline is found in two main geological occurrences. Igneous rocks, in particular granite and granite pegmatite and in metamorphic rocks such as schist and marble. Schorl and lithium-rich tourmalines are usually found in granite and granite pegmatite. Magnesium-rich tourmalines, dravites, are generally restricted to schists and marble. Tourmaline is a durable mineral and can be found in minor amounts as grains in sandstone and conglomerate.
Gem and specimen tourmaline is mined chiefly in Brazil and Africa. Some placer material suitable for gem use comes from Sri Lanka. In addition to Brazil, tourmaline is mined in Tanzania, Nigeria, Kenya, Madagascar, Mozambique, Namibia, Afghanistan, Pakistan, and Sri Lanka, and Malawi.
Almost every color of tourmaline can be found in Brazil, especially in the Brazilian states of Minas Gerais and Bahia. In 1989, miners discovered a unique and brightly colored variety of tourmaline in the state of Paraíba. The new type of tourmaline, which soon became known as paraiba tourmaline, came in unusually vivid blues and greens. These colors were often described as "neon" since they appeared to glow. Brazilian paraiba tourmaline is usually heavily included. Much of the paraiba tourmaline from Brazil actually comes from the neighboring state of Rio Grande do Norte. Material from Rio Grande do Norte is often somewhat less intense in color, but many fine gems are found there. It was determined that the element copper was important in the coloration of the stone.
Specific Gravity: 3.08
Streak: Whie
Variety: The rubellite is a particularly beautiful gemstone from the colourful family of the tourmalines. Its colour shines in the most beautiful nuances from red to shocking pink.
There are red and pink tourmalines in many nuances, which include a tender pink, a fine shocking pink, an intense violet and a bold ruby-red. However, only a few of these are entitled to call themselves 'rubellites'. The name comes from the Latin 'rubellus', which means reddish. Rubellites are not merely red or shocking pink tourmalines. There is an important criterion for this especially beautiful gemstone, and that is the way its colour behaves in daylight and artificial light. Many gemstones change their colour depending on the light source. A true rubellite does not. It shines just as intensely in artificial light as it does in daylight. The colour of most other pink or red tourmalines, by contrast, displays a more or less clearly visible tinge of brown in artificial lightCollection
Suomynona Mineral CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Width
4 inDepth
2-1/4 inLength
5 inWeight
1.74 ozDimension Notes
Dimension taken at widest pointsLocation
Category
PermanentMoved By
Curtis GardnerDate
May 25, 2023Notes
Added current location