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Today’s Specimen: Aegirine

Aegirine is a dark green to brown sodium iron silicate mineral, and is part of the clinopyroxine inosilicate group. It is often found within alkalic igneous rocks or pegmatites in the Northern hemisphere (Canada, Norway, Russia, and the USA, to name a few), as well as Nigeria. It has an approximate hardness of 5.0-6.0 on the Mohs scale. Aegirine is occasionally used as a faceting gemstone. Fun fact: Aegirine was named after the Norse god of the sea, Ægir. It is also referred to as acmite, a Greek name synonymous to “edged/pointed stone” in reference to the typical pointed formation of these minerals.

More about aegirine here.

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Today's Specimen: Dumortierite

Dumortierite is a violet to blue-green or brown mineral created by orthorhombic formations of aluminum boro-silicate. It can be found in mines across Peru, Austria, Brazil, Canada, Poland, France, Italy, Madagascar, the USA, Norway, Sri Lanka, Russia, Indonesia, and Namibia. Dumortierite is often used in the manufacturing of porcelain, and is frequently mistaken for sodalite* or lapis lazuli (see post on lapis lazuli here) Dumortierite has an approximate hardness of 7.0 on the Mohs scale, and can be polished and faceted. High quality faceted dumortierite can cost between $26-$90 USD per carat.

*Detailed information about this mineral coming soon.

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Today's Specimen: Emerald

Emerald is a green gemstone variety of beryl. The mineral gets its vibrant green colour from trace amounts of elements vanadium or chromium. Notable emerald mines can be found in Brazil, Columbia, Zambia, Zimbabwe, Russia, Pakistan, Madegascar, and Afghanistan. The largest single-crystal emerald ever found was discovered in Brazil in 2001, embedded in the magnificent Bahia Emerald. The Bahia Emerald is over 180,000 carats, weighing over 381kg (840 pounds), and has an estimated value of up to $940 million USD. This stone has a vast history, notably being smuggled to the United States in 2005, causing an intense "custody battle" over the gemstone. Emerald has an average price of about $169 USD per carat, and is among the most sought after gemstones for faceting. With a hardness of about 7.5-8.0 on the Mohs scale, it is a great choice for a bold statement or simple jewelry piece.

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Today's Specimen: Moganite

Moganite is a tectosilicate mineral, originally found in Mogán, Canary Islands. Moganite is usually grey in colour. In 1994 the International Mineralogical Association (IMA) declassified moganite as an official mineral, since it was virtually impossible to differentiate from quartz. In 1999, moganite was reclassified as a mineral species by the IMA. Moganite has the same chemical composition as quartz (SiO2), but forms in a different structure. Moganite can be found across European countries, as well as the USA and India. It has a usual hardness of 6.0 on the Mohs scale, and can be utilized much the same as quartz.

More about moganite here.

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Today's Specimen: Fluorite

Fluorite is the mineral form of Calcium Fluoride, and is classified as a halide mineral. Fluorite can be found in many rainbow colours, as well as black, brown, white, and pink. Pure fluorite, with no other inhibiting minerals, is colourless. Fluorite is often used for ornamental (jewelry) and industrial (production of some glass, hydrofluoric acid) purposes. The first evidence of fluorite's existence is mentioned in a text from 1530 by Georgius Agricola. Fluorite has properties of both a thermoluminescence and fluorescent glow, the latter of which was actually named after the mineral. Fluorite mines can be found in Canada, Rwanda, China, the UK, South Africa, Mongolia, Argentina, Tanzania, Germany, and Namibia. Fluorite is about a 4.0 on the Mohs hardness scale. Fluorite is alternatively referred to as Fluorspar.

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Fossil Friday: Ammonite

Ammonite is a preserved shell belonging to an Ammolite or other creature belonging to the subclass Ammonoidea. These fossils are the remains of an extinct marine cephalopod (mollusc) from the Jurassic period (about 200 million years ago) to the late Cretaceous period (about 66 million years ago). Ammonites died off at roughly the same time as flightless dinosaurs. Ammonites were a unique group of creatures, likely having eight separate arms, resembling a coleoid (squids, octopuses, and cuttlefish), while the shell and it's shape closer resembling a nautilus. An estimated 10-20 thousand species of ammonite have been discovered, so no two fossils will be the same. The largest ammonite specimen found was over 1.8 metres (approx. 5.9 feet) in length, while being an incomplete fossil. Ammonite can be found at any location where prehistoric oceans once were. Ammonite is often used as an index fossil, being used to date the approximate age of the rocks it is embedded in. Ammonite is considered to be one of the world's rarest gemstones when the shell appears iridescent.

It is crucial to be aware of laws and regulations governing fossil collection in your area. Many places require all fossils found to be sent to a palaeontologist, and have strict regulations on the selling of locally found specimens.

More information about ammonites can be found here.

Stay tuned for next week's Fossil Friday!

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Today's Specimen: Purpurite

Purpurite is a violet to deep red manganese phosphate mineral that contains various amounts of iron depending on the location mined. Purpurite is the lithium-deficient oxidation material produced by lithiophilite. Purpurite appears almost metallic, with an iridescence when hit with light at the right angle. The mineral is named after the latin word for purple, purpura. Purpurite is a relatively rare stone, discovered in 1905 in North Carolina, USA. Purpurite mines can be found in the USA, France, Namibia, Portugal, Rwanda, Malaysia, and Australia. This stone has a hardness of about 4.0-4.5 on the Mohs scale, making it relatively soft and not a common material for faceting, while still being used for jewelry on occasion.

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Today's Specimen: Pyrite

Pyrite is the most common sulfide mineral worldwide, consisting primarily of iron and sulfur. Pyrite forms in unique patterns, which change drastically depending on the environment it forms in, ranging from stalactitic to globular and many forms in between. These minerals can be found globally, with notable deposits being in the United States and several locations around the Iberian Peninsula in western Europe. Pyrite is often referred to as "fool's gold", considering that it is frequently mistaken for gold by the untrained eye.

Pyrite vs. Gold:

A major differentiating factor between gold (shown below) and pyrite (shown at top) is hardness and malleability. Pyrite has a hardness of 6.0-6.5 on the Mohs scale, making it relatively difficult to scratch. Gold has a hardness of only 2.5, making it extremely easy to mold, scratch, and bend. Pyrite is occasionally accompanied by small amounts of gold, however not concentrated enough to be considered a reliable source material. Gold and pyrite also differ between their formation structures, caused by reactions with their respective elements. Gold forms in flakes or nuggets, and are usually found in small quantities, while pyrite forms in considerably larger amounts and in more complex angular shapes.

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Today's Specimen: Lapis Lazuli

Lapis lazuli is a semi-precious metamorphic stone, sought after for its intense blue colour. Lapis lazuli, more simply known as lapis, consists of pyrite (see post about pyrite here), calcite*, and lazurite*. (lazurite is what gives lapis that bright blue colour seen above.) Lapis lazuli can be found in mines across the globe, including: Afghanistan, Chile, Russia, Canada, Angola, Argentina, Pakistan, Italy, India, the USA, and Myanmar (prev. Berma). Lapis lazuli has been used practically since as early as 7000 BCE for worship purposes. Since then, the mineral has been used to make the ultramarine pigments used by Renaissance and Baroque artists, as well as jewelry, decorative pieces, and has notably been found in the funeral mask of Egyptian pharaoh Tutankhamun. Lapis has a hardness of 5.0-5.5 on the Mohs hardness scale. Lapis lazuli gemstones can be sold for less than $1 USD per carat for low grade pieces, and up to $150 USD per carat for superfine pieces.

*Detailed information about this mineral coming soon.

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Today's Specimen: Childrenite

Childrenite is a hydrated phosphate mineral consisting of iron, manganese, aluminum, phosphorus, oxygen, and hydrogen. It is usually translucent in shades of yellow or brown, but can also be colourless. It can be found in granite pegmatites and hydrothermal vein deposits in Brazil, the UK, the USA, and Germany. Childrenite has a pyramidal formation structure, and is considered a semi-precious gemstone. Childrenite normally retails for about $30-$70 USD per carat, making it one of the most affordable gemstones.

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Today's Specimen: Galena

Galena is a natural lead ore and a common source of silver. It is one of the most abundant sulfide minerals. Galena forms in cubic patterns, creating a blocky texture. Because lead is an extremely dense material, galena is particularly heavy. It has a hardness of 2.5 on the Mohs scale, making it rather fragile. Galena is used not only as a lead source, but also as a semiconductor and cosmetic ingredient. Alternate names for galena include: Lead Glance.

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Today's Specimen: Rose Quartz

Rose quartz is a common pink to rose red variety of quartz. It is considered a semi-precious gemstone. Rose quartz has been used for beads and jewelry since about 7000 BCE. It is about a 7.0 on the Mohs hardness scale, making it a durable and versatile stone. Rose quartz is considered a symbol of love and healing.

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Today's Specimen: Cerussite

Cerussite is a lead-based mineral formed by carbonated water on the mineral galena (see post about galena here). It can be found in Namibia, Spain, the USA, and Australia. Cerussite is a secondary source of lead, and can be used (less frequently nowadays after the discovery of negative long term side effects to lead exposure) as a key ingredient in paints, bullets, batteries, cosmetic products, and plumbing. It is often white, yellowish, or colourless, but can also occasionally appear in grey, blue, or green. Cerussite uniquely reflects light in a phenomenon called dispersion, creating kaleidoscope-like effects. It also creates a fluorescent yellow hue when exposed to ultraviolet light, with its vibrancy relying on its heavy lead content. Cerussite should be handled carefully and minimally, with personal protective equipment, to reduce risk of lead-based illnesses and symptoms. Alternate names for cerussite are: White Lead.

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Today's Specimen: Agate

Agate is a banded chalcedony, known by vibrant colours and distinctive patterns. Agate can be found in nearly every colour, with the rarest being purple and the most common being neutral reddish greys and yellows. Agate can be found worldwide, while colour and vibrancy often depend on its country of origin and environmental factors of that area. It is commonly dyed to appear brighter and more colourful, even though agate is already found in a multitude of shades. It is often found in the outer layers of geodes, and frequently accompanied by magnificent druzies (pockets of crystal formed within the mineral). Agate has a hardness of about 6.5-7.0 on the Mohs hardness scale, making it a decent choice for jewelry makers. Some of the many subtypes of agate include: Lace Agate, Polyhedroid Agate, Coldwater Agates, Brazilian Agate, Turritella Agate, Holley Blue Agate, Fire Agate, and many more.

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(Sorry for missing yesterday, life got a little busy but I love you all!)

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Today's Specimen: Halite

Halite is a rock you've most definitely seen before, but likely not the name you've heard. Halite is viewed as the most well known mineral in the world. That's right, this is your average table salt! It is formed in a cubic pattern, and can be found almost anywhere, from lakes to springs to oceans, there is halite. The word halite comes from the Greek word halos, meaning salt. Halite is used as a flavour enhancing ingredient in food, as well as for things like de-icing and industrial chemicals. Fun facts: Ancient Roman soldiers were paid in salt as well as gold. Miners at the Wieliczka Salt Mine in Poland have gotten creative with their work, and made it tradition to carve sculptures into the halite caves! Next time you sprinkle salt on your dinner, take a moment to think about just how magnificent it is, and what a great job it does!

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Today's Specimen: Labradorite

Labradorite is a feldspar mineral rich with calcium. Originally discovered in Labrador, Canada, it was named after the territory. Other notable occurrences of labradorite outside of Canada include Poland, Norway, Finland, China, Madegascar, Australia, the USA, and Slovakia. Labradorite is uniquely iridescent, and colours may shift and vary depending on the specimen. It is viewed by many indigenous groups as being the aurora borealis encapsulated by stone. It is a 6.0-6.5 on the Mohs hardness scale. Alternate names for labradorite include: Spectrolite, Black Moonstone, and Rainbow Moonstone.

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Today's Specimen: Lepidolite

Lepidolite is a usually lilac or rose coloured mica, and a major source of lithium and rubidium. It can be found in Brazil, Russia, the USA, Canada, and Madegascar. Since it is a mica, it forms in thin sheets. It is often embedded with quartz, and used as a minor gemstone. Lepidolite is occasionally used to make glass as an ingredient in enamels. Lepidolite has an average hardness of 2.5 on the Mohs hardness scale, but when impregnated with quartz is significantly more durable for jewelry use.

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