Thursday, June 20, 2013

Madagascar and its Minerals

Many of those who have visited the Gitche Gumee Museum know that in addition to local rocks and minerals, I feature minerals from all over the world.   Three of the most popular minerals I sell are from Madagascar.  These include Ocean Jasper, which was introduced to the world at the Tuscon show in 2000. This mineral is a variety of jasper which contains variably-colored orbs or spherical inclusions or zones.  Ocean Jasper formed in highly silicified volcanic rhyolite or tuff when quartz and feldspar molecules developed in radial aggregates of needle-like crystals which provided the basis or seed for the orbicular structure seen in this kind of jasper.  Ocean Jasper was found in only one place in the world, a site along the northwest coast of the African island Madagascar. The location which held the Madagascar ocean jasper was only reached by boat when the tide was low.  Unfortunately, the deposit was quite small and has been mined out since 2006.

The pictures below I took at the Tuscon show:

After the deposit of Ocean Jasper was mined out, the mining companies scrambled and looked for more deposits.  They did not find any more Ocean Jasper, but they did find a brand new mineral called Polychrome Jasper. 

More recently another mineral has been found in Madagascar.  There is a special variety of labadorite called spectralite.  It has more "flash" than labadorite that is exhibited in a wide variety of color.  Previously, most of the spectralite was from Finland.  Unlike ocean jasper and polychrome that is found in the northern part of Madagascar, the spectralite deposit is in the center of the island.

Madagascar and previously known as the Malagasy Republic, is an island country in the Indian Ocean, off the southeastern coast of Africa. The nation comprises the island of Madagascar (the fourth-largest island in the world), as well as numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from India around 88 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90 percent of its wildlife is found nowhere else on Earth. Unfortunately, the island's diverse ecosystems and unique wildlife are threatened by the encroachment of the rapidly growing human population.
Initial human settlement of Madagascar occurred between 350 BC and 550 AD by Austronesian peoples arriving on outrigger canoes from Borneo. These were joined around 1000 CE by Bantu migrants crossing the Mozambique Channel. Other groups continued to settle on Madagascar over time, each one making lasting contributions to Malagasy cultural life. The Malagasy ethnic group is often divided into eighteen or more sub-groups of which the largest are the Merina of the central highlands.  The main ethnic groups are:
  • 26% Merina
  • 15% Betsimisaraka
  • 12% Betsileo
  • 7% Tsimihety
  • 6% Sakalava
  • 5% Antaisaka
  • 5% Antandroy
  • 24% French and others

    Until the late 18th century, the island of Madagascar was ruled by a fragmented assortment of shifting socio-political alliances. Beginning in the early 19th century, most of the island was united and ruled as the Kingdom of Madagascar by a series of Merina nobles. The monarchy collapsed in 1897 when the island was absorbed into the French colonial empire, from which the island regained independence in 1960. The autonomous state of Madagascar has since undergone four major constitutional periods, termed Republics. Since 1992 the nation has officially been governed as a constitutional democracy from its capital at Antananarivo. However, in a popular uprising in 2009 the last elected president Marc Ravalomanana was made to resign and presidential power was transferred in March 2009 to Andry Rajoelina in a move widely viewed by the international community as a coup d'état.

    In 2012, the population of Madagascar was estimated at just over 22 million, 90 percent of whom live on less than two dollars per day. Malagasy and French are both official languages of the state.

    Other Madagascar facts:

  • Madagascar is the fourth largest island in the world, approximately 226,656 square miles (587,040 square kilometers). The only larger islands are Greenland, New Guinea and Borneo.
  • Madagascar has two seasons, a hot rainy season which starts in November and last until April and a cooler dry season which starts in May and last until October.
  • One of the most interesting Madagascar facts listed here is that almost all OF the animal and plant species found on the island are unique to the island. These plants and animals have evolved into some of the oddest forms found on earth.
  • There is a tropical rain forest on the eastern side of the island.
  • The capital of Madagascar is Antananarivo. It is also the islands most populated city.
  • Madagascar is a poor country. The people face many problems including malnutrition, poor health care, and a poor educational system.
  • The island has a narrow coastal plain which gets higher as it gets inland. In the center of the island are mountains.  The islands highest mountain is Maromokotro. It is 2,876 meters high (9,435 feet).
  • Most of the population (52%) maintain their indigenous religious beliefs, 41% are Christian, and 7% are Islam.
  • Millions of years ago Madagascar was part of the African continent. Over time it broke away and reached the location it is in now (approximately two million years ago).
  • Madagascar has lost approximately ninety percent of its original forest land since humans arrived on the island about two thousand years ago.
  • Madagascar was home to the largest bird in the world, the elephant bird, until it became extinct in the 17th century. It is believed to have been over ten feet tall (3 meters).



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