It’s all in the Family: Beryl Addition
by Lauren Sypolt
What comes to your mind when you think of the world Beryl? If you put a real southern twist on it, you might think someone said barrel. Or if you are a Sailor Moon Fan, you might think of the evil space
Queen Beryl and her soldiers: Jadeite, Nephrite, Zoisite, and Kunzite. (Only after they were taken over by Metalia’s negative energy.
Sailor moon Villain: Queen Beryl
Ah, 90s nostalgia.
Technically Queen Beryl’s soldiers should have been named: Emerald, Aquamarine, Morganite, and Heliodor. But why would her soldiers have these names instead? Because all four of these gemstones are a part of the beryl family.
Definition of a beryl gemstone: Beryl is a relatively rare silicate* mineral with a chemical composition of Be3Al2Si6O18. It is found in igneous* and metamorphic* rocks in many parts of the world.
*Silicate: a silicone – oxygen compound. The silicates make up about 95 percent of Earth’s crust and upper mantle, occurring as the major constituents of most igneous rocks and in appreciable quantities in sedimentary and metamorphic varieties as well. They also are important constituents of lunar samples, meteorites, and most asteroids. (1)
Silicate - I'm sure this makes sense to someone but I failed chemistry. So, I'm taking Wiki's word that is it what is says it is.
*Igneous: Igneous rocks (from the Latin word for fire) form when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. (2)
*Metamorphic: Metamorphic rocks form when high temperatures and pressure act on a rock to alter its physical and chemical properties (metamorphism means 'to change form'). These conditions often stretch, twist and fold the rock as it cools. In metamorphic rocks some or all of the minerals in the original rock are replaced, atom by atom, to form new minerals. Types of metamorphic rocks include gneiss, quartzite, marble, schist, soapstone, and phyllite. (5)
Wow, that’s a lot of definitions. Yes. But to understand the complex and beautiful beryl family, we have to know their back story. What makes beryl gemstones, what they are?
Let’s start with Igneous Rocks: What are some examples of igneous rocks? Well, for starters there are two different types of igneous rocks.
- Intrusive Igneous Rock: Intrusive igneous rocks are rocks that crystallize below the earth’s surface resulting in large crystals as the cooling takes place slowly. Diorite, granite, and pegmatite are examples of intrusive igneous rocks. (4)
- Extrusive igneous rocks are rocks that erupt onto the surface resulting in small crystals as the cooling takes place quickly. The cooling rate for a few rocks is so quick that they form an amorphous glass. Basalt, tuff, pumice are examples of extrusive igneous rock. (4)
Example: Granite = expensive countertops.
So what does beryl have to do with igneous rocks and metamorphic rocks? Because these two types of rocks is where beryl occurs.
Example: Beryl is a common mineral, and it is widely distributed in nature. It found most commonly in granitic pegmatites, but also occurs in mica schists, such as those of the Ural Mountains, and in limestone in Colombia. (6) In granitic pegmatites, beryl is found in association with quartz, potassium feldspar, albite, muscovite, biotite, and tourmaline. Beryl is sometimes found in metasomatic contacts of igneous intrusions with gneiss, schist, or carbonate rocks. (7)
Ruggles Mine in New Hampshire.
Fun fact about igneous rocks? The size of mineral crystals in an igneous rock may indicate the rate at which the lava or magma cooled to form a rock. (4)
Woah. Woah. Woah. That’s too much information.
That’s true. That’s a whole lot of scientific facts when all we came here to do was talk about emeralds and sailor moon villains.
Well, I wanted to give some information on the beryl family because it’s kind of hard to understand how emeralds (green), aquamarine (blue), morganite (pink), and helidor (yellow) can all come from the same family of gemstones. And they aren’t adopted. All of these gemstones are a part of the beryl family, the only difference is the minerals around them when they formed.
Minerals? Formed?
Beryl belongs to the hexagonal crystal system. Normally beryl forms hexagonal columns but can also occur in massive habits. As a cyclosilicate beryl incorporates rings of silicate tetrahedra of Si6O18 that are arranged in columns along the C axis and as parallel layers perpendicular to the C axis, forming channels along the C axis. These channels permit a variety of ions, neutral atoms, and molecules to be incorporated into the crystal thus disrupting the overall charge of the crystal permitting further substitutions in aluminum, silicon, and beryllium sites in the crystal structure. These impurities give rise to the variety of colors of beryl that can be found. (8)
What does that even mean?
Basically it’s a lot of scientific talk about how a beryl is formed. A cyclosilicates is a ring of silicates and has there or more therahedra linked in a ring. A therahedra is a triangular pyramid. This is all just describing the molecular shape of beryl. This is how geologist identify what gemstones fall into the beryl family.
Emeralds – We are green with envy.
What makes an emerald green?
Trace amounts of chromium or vanadium in the mineral cause it to develop a green color. Trace amounts of iron will tint emerald a bluish green or a yellowish green. (9)
Aquamarine – the gemstone of our ocean filled dreams.
So what makes aquamarine blue?
The name aquamarine comes from two Latin words aqua marinus meaning “water of the sea”. The color comes from trace amounts of iron in the stone. Aquamarine is typically greenish blue in nature, so it is heat treated to remove the yellow component, and to produce a true-blue color. (10)
Morganite – A beautiful pink. Am I right?
What makes morganite pink?
Morganite’s subtle color is caused by traces of manganese. Because morganite has distinct pleochroism—pale pink and a deeper bluish pink—it’s necessary to orient the rough carefully for fashioning. Strong color in morganite is rare, and gems usually have to be large to achieve the finest color. (11)
Heliodor – Helios like the brightest yellow sun.
Why so yellow heliodor?
What makes heliodor different than other yellow shades of beryl, is that it gets its vibrant color from trace iron impurities. (12)
But iron is the main color contributor to both aquamarine and heliodor? How can it cause one to be blue and the other to be yellow?
That is an excellent question!
And I have no idea. My small brain can’t really get my head around it all. But here is an exactly link to a study done by GIA. God speed on interpreting what they are saying.
GIA Link:
https://www.gia.edu/gems-gemology/spring-2020-color-characteristics-blue-to-yellow-beryl
So what was the point of this blog?
A wee bit of informative information on the beryl family. And basically a cathartic way of me trying to learn this information myself and to look at pretty pictures of gemstones.
By Lauren Sypolt
Resources:
(1) https://www.britannica.com/science/silicate-mineral
(2) https://www.usgs.gov/faqs/what-are-igneous-rocks
(3) https://www.usgs.gov/faqs/what-are-metamorphic-rocks
(4) https://byjus.com/physics/igneous-rocks/
(5) https://www.nps.gov/subjects/geology/metamorphic.htm
(6) Klein, Cornelis; Hurlbut, Cornelius S. Jr. (1993). Manual of mineralogy : (after James D. Dana) (21st ed.). New York: Wiley. p. 472. ISBN 047157452X.
(7) Nesse, William D. (2000). Introduction to mineralogy. New York: Oxford University Press. p. 301. ISBN 9780195106916.
(8) Klein, Cornelis; Dutrow, Barbara; Dana, James Dwight (2007). The Manual of Mineral Science : (after James D. Dana) (23rd ed.). Hoboken, N.J.: J. Wiley. ISBN 978-0-471-72157-4. OCLC 76798190
(9) https://geology.com/gemstones/emerald/
(11) https://www.gia.edu/morganite#:~:text=Morganite's%20subtle%20color%20is%20caused,to%20achieve%20the%20finest%20color.
(12) https://www.jewelsforme.com/gem_and_jewelry_library/heliodor