I trust you know what to do with this rather peculiar file attachment. - The MiB

EMERALD SUMMARY

Chemical Composition: Be3Al2(SiO3)6
Class: cyclosilicates
Crystal system: hexagonal; 6/m2/m2/m
Crystal habit: Typically small elongate first order prisms, often with vertical striations and irregular pinacoidal terminations
Specific gravity: 2.67 - 2.78
Index of refraction: 1.566 - 1.602
Birefringence: 0.005 - 0.008
Pleochroism: distinct, blue-green/yellow-green
Hardness: 7.5 - 8.0
Color: deep green, can have slightly yellowish or blueish tones
Luster: vitreous
Transparency: translucent to opaque, very rarely transparent
Cleavage: poor basal cleavage is seldom visible on {0001}
Fracture: conchoidal producing smooth brilliant surfaces, brittle
Streak: white

MYTHOS FACTS

For the most part, trapiche emeralds are a man's stone. And its biggest following is amongst men of Colombia and Japan.

The Incas originally mined emerald in Colombia as early as the 17th Century.

The Egyptians of earlier years credited emerald with fertility and rebirth.

Emerald was also thought to repel demonical influences!

DESCRIPTION

Emerald - Medium to dark green beryl which derives its color from chromium (some gemologists argue that dark green beryl colored by vanadium should be called emerald, and others insist that chromium must be present). The best known sources include Colombia, Zambia.

Almost all emeralds contain numerous small inclusions and fractures that promote fragility. Most stones on the market are impregnated with oils, waxes, or other substances to mask the fractures and sometimes enhance color. Such stones should never be cleaned with ultrasound, as it may remove or damage the impregnating substance. Emeralds of fine color and clarity can be quite expensive.

Trapiche emeralds are in a class by themselves. Found only in the celebrated Muzo mining district of Colombia, these are perhaps the rarest of "pattern" gems, and certainly the most unusual amongst the big three (emerald, ruby, and sapphire). Their six spoke-like carbon "rays" emanating from a hexagonal center with the areas in between filled with lively emerald green makes this a gem you'll never forget once you see one.

The earliest reference to trapiche emeralds was in an 1879 French mineralogical bulletin. It was more than 36 years later before it appeared again, remarkable because such literary greats as George Kunz were writing much around the turn of the Century.

Trapiche is the Spanish word for a spoked wheel used to grind sugar cane which bears a striking resemblance to the pattern in these emeralds. It is pronounced trah-pee-chee with the accent on the second syllable.

There are two types of trapiche emeralds. The "A" type is under 2-carats and has bands of lighter emerald separating the sections. The more prized "B" type ranges from 2 to 50 carats and has distinct carbon bands.

Trapiche emeralds are valued based on a number of factors. The most important is the definition, completeness, and centering of the "rays." A close second factor is the color of the emerald which ideally is deep, saturated, and even. And third, and also q uite important, is the quality of the cut. You have to see our trapiche to appreciate the quality it has on all three counts: the rays are clean and distinct, the color is intense and even, and the cut is superb including some sculpturing underneath to add appeal and eliminate unnecessary weight.

Source:

MineralMiners.com


"Chris Williams"
Subject: DG: MiB's .sig
Date: Fri, 11 Jun 1999 01:42:27 BST

The ever-lovin' blue-eyed MiB wrote:
> [Be3Al2(SiO3)6] : [Crystal system: hexagonal; 6/m2/m2/m ]
Alright, a new brainteaser! Um, lets see... Beryllium, Aluminium, Silicon triOxide... sounds like another freaky-chemical-thing (TM). Nothing in the online chemical databases, but that's not unusual...
The rest sounds like a way of describing the molecule. Well, that's me stumped early, isn't it?


Majamane
Subject: Re: DG: MiB's .sig
Date: Thu, 10 Jun 1999 22:01:37 -0300
[Delurking]

It's Beryl, a form of which is Emerald, it has a hexagonal crystal form. However I haven't found out the last part of the sig yet.

[Lurking mode reacitvated]


"Chris Williams"
Subject: Re: DG: MiB's .sig
Date: Fri, 11 Jun 1999 01:57:39 BST

D'oh! Two seconds after I say I can't find it, I find it. And boy do I feel stupid. Be3Al2(SiO3)6 is Beryl. It has a hexagonal crystal system class 6/m2/m2/m. It can be green, blue, yellow, colourless, or pink. Green beryl comes from Columbia, and is better known as Emerald.


"JimmieBise,Jr"
Subject: Re: DG: MiB's .sig
Date: Thu, 10 Jun 1999 22:45:32 -0400

And somewhere there's a "Hammer" Reference coming.....(You Can't Touch this?)