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Crystal of Brazilianite, length ~1.1 cm.
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By
the time I have money to burn, my fire will have burnt out.
(Author
Unknown)
Well, I don’t have money to burn and my fire still
seem bright. But, if I did have excess
monetary resources I would collect gemstones, especially gemstones that are
usually only cut for collectors. But
since that “ain’t goin” to happen, I try and pick up a few crystals of these
sort of different minerals. And by different, I
simply mean rather uncommon minerals that I can’t seem to locate here in rocks
of the Pikes Peak Batholith. If they are gemmy, so much the better. So, it is
with great anticipation that I visit rock and mineral shops throughout my travels---always on the lookout for bargains. What I
usually find are thumbnails or so and not large cabinet specimens. That is OK since I do not have room for many
larger specimens!
One recent leaf peeping trip led me to a mineral
shop where I was able to purchase a brazilianite crystal since it was a new
mineral to me, and it was sort or “purdy”. Brazilianite is one of the many phosphate
mineral (contains the PO4 radical with a -3 charge) that
I have come to enjoy reading about, if not locating specimens. The phosphate minerals that we are most familiar
with probably belong to Apatite Group (calcium phosphate) although most
collectors have specimens of turquoise (copper aluminum), wavellite (aluminum),
and pyromorphite (lead). Monazite
(cerium, lanthanum, yttrium, and thorium) and xenotime (yttrium) are part of
the “rare earth” phosphates. There are
many other minerals that belong to the very broad Phosphate Class where arsenate
(AsO4), hydroxide (OH), fluorine (F), chlorine (C), and vanadate (VO4)
often substitute into, or are part of, the chemical composition; however, that is a
story for a later time.
So, I sprung for the brazilianite crystal, brought
in home, and tried to learn more. It is
a sodium, aluminum, phosphate with a hydroxide radial attached [NaAl3(PO4)2(OH)4]. My specimen is sort of a yellow-green color,
vitreous luster, mostly transparent, gemmy looking, and with many faces
striated. The crystal does not appear to
have any symmetry and they look very complex—a short wedge shape. When initially located collectors often confused brazilianite with similar looking chrysoberyl (Be2AlO4).
The mineral was first noted in Brazil, hence the
name. It is usually found in phosphate-rich
pegmatites, not a particularly common rock type. Up in the Black Hills the Tip Top Mine
produces a variety of these strange/uncommon phosphate minerals, most of them
micromounts. That mine is “world famous”
and in excess of 90 minerals, with 12 type-locality minerals, are found there
(Lufkin and others, 2009). However,
MinDat.com shows the only brazilianite in the Hills come from the Dan Patch
Mine. In the U.S, the Palermo Mine in New
Hampshire seems to have provided the best crystals of brazilianite (and many
other rare phosphate minerals). The mineral
has not been located in Colorado.
My specimen is from Linopolis, Divino das Laranjeiras, Doce Valley, Minas Gerais, Brazil--this is the "type locality" for the mineral. The locality is known as the Eastern Brazil Pegmatite Province.
I have seen photos of faceted gemmy brazilianite and
they are spectacular; however, it is relatively soft (~5.5 Mohs) and rarely
used in jewelry. In addition, lapidaries must be very careful when working with the mineral since it chips easily and often breaks along the cleavage plane.
Hence, my “desire” to collect gemstones that are only cut for collectors. I believe that everyone collects. I think collecting is in our blood as humans (Lynda Resnick).
Hence, my “desire” to collect gemstones that are only cut for collectors. I believe that everyone collects. I think collecting is in our blood as humans (Lynda Resnick).