Quartz Species Part 2 - Amethyst & Amethyst Quartz

Hi everyone, 

In today's blog I would like to talk about Amethyst and Amethyst quartz.  I really like the dark purple colour of amethyst.  I find it to be very relaxing and soothing.  I also find it interesting that amethyst also comes in a green colour.  If you are not aware amethyst is the birthstone for people born in February.  If I was a February baby I would like the fact that my stone comes in different colours.  I hope that you will follow me on the journey that is amethyst and I hope you learn something new and exciting.

So lets talk amethyst.  As before all the information that I am using for this blog can be found in the book Gemstones of the World by Walter Schumann.  The colour ranges for amethyst are purple, violet, pale-red violet.  The colour streak is white and the Mohs hardness is 7.  The density is 2.65 and there is no cleavage.  The crystal system is trigonal, hexagonal prisms.  The chemical composition is silicon dioxide.  The transparency is transparent.

In the quartz group amethyst is the most highly valued gemstone.  The name is derived from the Greek meaning not drunken.  Because of this the gemstone was worn as a protection against drunkenness.  Amethyst crystals are always grown onto a base and the prisms are not usually well developed, because of this the amethyst crystals are often found as crystal points, called pointy amethyst.  These crystals often have the deepest colour.  When amethyst is heat treated between 878 and 1382 degrees F it produces light yellow, red-brown, green or colourless varieties.  The colouring agent in amethyst is iron.

The amethyst gemstones are found in geodes in alluvial deposits.  Brazil had the most important deposits. The main place is Rio Grande do Sul which has the Palmeira amethyst and Para which has the maraba amethyst.  Other places where amethyst can be found are Madagascar, Zambia, Uruguay, Burma, India, Canada, Mexico, Namibia, Russia, Sri Lanka, and the United States.  The best stones that are found are the ones that are faceted the others are tumbled or worked into ornaments.  Amethysts used to be a favourite gemstone of the high officials of the Chrisitan Church.

Another type of quartz related to the amethyst is the ametrine, which can also be called trystine.  This type of gemstone is a colour zone quartz variety.  The gemstone consists of half amethyst and half citrine.  This gemstone is found in Brazil and Bolivia.

Amethyst Quartz is violet with whitish stripes.  The colour streak is white and the Mohs hardness is 7. The density is 2.65 and it has no cleavage.  The crystal system is trigonal, hexagonal prisms and the chemical composition is silicon dioxide.  The transparency is transparent.  The amethyst quartz is the rougher form of amethyst.  It is also more compact.  This stone is layered and striped with milky quartz.  These gemstones are formed with amethyst.   The most common uses for amethyst quartz are beads, baroque stones, cabochons and ornamental objects.

I hope everyone who reads this post enjoys it as much as I enjoyed writing it.  I hope you learned something new and interesting.  Please let me know what you think of this blog.  I would like to hear from like minded individuals.  Until next time.

The rare gem lady

Quartz Species Part 1 Rock Crystal and Smoky Quartz

Hi everyone,

Today I would like to discuss the quartz family.  There are many parts to the quartz family so this will also be a multi-part series.  I hope it is easier for everyone if I group the different types of quartz and talk about them separately.  I, myself find it easier to discuss the various groups if they are broken up into smaller sections.  This also allows for the material to be absorbed better.  As before all the information that I am writing about is found in the book Gemstones of the World by Walter Schumann.

The word quartz is derived from the Slavic word for hard.  It is the name for a group of minerals that have the same chemical composition.  The Macrocrystalline quartz are crystals recognizable with the naked eye.  This type of quartz has the gemstones amethyst, aventurine, rock crystal, blue quartz, citrine, hawk's eye, prasiolite, quartz cat's eye, smoky quartz, rose quartz and tiger's eye.  Cryptocrystalline quartz are microscopically small crystals.  The gemstones included in this type of quartz typically known as chalcedony are: agate, petrified wood, chrysoprase, bloodstone, jasper, carnelian, moss agate and sard.

Rock crystal is a colourless stone, the colour streak is white and the density is 2.65.  The Mohs hardness is 7 and there is no cleavage. The crystal system is trigonal, hexagonal prisms.  The chemical composition is silicon dioxide and the transparency is transparent.  The name comes from the Greek meaning ice.  Cuttable rock crystal material is rare.  This gemstone can be found in Brazil, Madagascar, the United States and the Alps.  This stone is used primarily for costume jewellery and bowls and vases.

Smoky quartz is named after the smoky colour.  The very dark stones are called morion and caingorm.  The colour is brown to black, smoky grey.  The colour streak is white and the density is 2.65.  The Mohs hardness is 7 and there is no cleavage.  The crystal system is trigonal, hexagonal prisms.  The chemical composition is silicon dioxide and the transparency is transparent.  The name smoky topaz is no longer recognized in the trade to describe smoky quartz.  There are frequent inclusions of rutile needles in smoky quartz.  This gemstone can be found in Brazil, Madagascar, Russia, Scotland, Switzerland and the Ukraine.  It uses are the same as for rock crystal.

I hope everyone learned something new and exciting about rock crystal and smoky quartz.  I know that I did and I hope everyone had fun learning.  I am really enjoying writing this blog about gemstones.  I find that I am learning something new everyday and that is what is making this so rewarding for me.  I hope that you will drop me a line and let me know how I am doing. I would love to hear from you.  Until next time.

The rare gem lady

Beryl Species Part 3 Precious Beryl

Hi everyone,

Today I would like to finish up the section on Beryl.  We will be looking at the precious beryl family.  These gemstones are the ones that are not emerald and aquamarine.  I hope you will enjoy the journey of learning today and I hope you will learn something new and exciting about precious beryl.  I, myself am not really familiar with precious beryl so this blog will bring many new and exciting information for me to learn.  I hope you have fun on the journey of precious beryl.

So let's talk precious beryl.  The information I am using is from the book Gemstones of the World by Walter Schumann. The colours of precious beryl range from gold-yellow, yellow-green, yellow, pink and colourless.  The colour streak is white and the Mohs hardness is 7.5-8.  The density is 2.66-2.87.  The cleavage is indistinct and the chemical composition is aluminum beryllium silicate.  The transparency is transparent to opaque. The crystal structure is hexagonal, hexagonal prisms.

According to Mr. Walter Schumann, precious beryl refers to all colour varieties of the beryl group that are not emerald or aquamarine.  These gemstones are brittle and are sensitive to pressure.  There are special names for some of the colours.  Bixbite is for the raspberry red colour of beryl.  The origin of the name is not known. Because of this there are many scientists that do not accept bixbite as a separate variety.  Golden Beryl has the colour range of lemon yellow to golden yellow.  Inclusions in this gemstone are rare.  Golden Beryl is found in Brazil, Madagascar, Namibia, Nigeria, Zimbabwe and Sri Lanka.  Goshenite is the colourless beryl and is so named because it is located in Goshen, Massachusetts.  It has been used as an imitation diamond.  It can also be used for an imitation emerald by applying silver or green metal foil to the cut stone.  It can be found in Brazil, China, Canada, Mexico, Russia and the United States. Helidor is Greek for present of the sun.  This gemstone is a light yellow green colour.  The gemstone was discovered in 1910 in Namibia but there have been other beryls of the same colour discovered previously in Brazil and Madagascar.  Helidor is generally not accepted as it is hard to distinguish between the yellow and green yellow colours of golden beryl, so it is considered as being weak coloured golden beryls.  Morganite also known as pink beryl has the soft pink to violet colours.  Inclusions are rare in this gemstone.  Morganite is named after the American banker J.P. Morgan.  This gemstone is found in Afghanistan, Brazil, China, Madagascar, Mozambique, Zimbabwe, and the United States.

I hope everyone had fun learning about the wonderful world of Precious Beryl.  I know I learned quite a few new things and had a great time learning about them.  Please let me know what you think of this post.  I would really enjoy hearing from you so please drop me a line.  Until next time.

The rare gem lady

Beryl Species Part 2 Aquamarine

Hi everyone,

Today I would like to talk about the next gemstone in the beryl family which is Aquamarine.  For those of you who have a March birthday like me then you know that this is your birthstone.  When I was growing up I hated my stone.  I thought it's colour was like a washed out sapphire.  I had always wanted to be a May baby because their birthstone was emerald.  But as I grew up, I began to realize what a special colour the aquamarine is and now I do not mind having it as my birthstone.  So I would like to discuss my birthstone today.  I hope you will join me on this journey of learning and discovering.

So let's talk aquamarine.  The colour is light blue to dark blue, blue-green.  The colour streak is white.  The Mohs hardness is 7.5-8 and the density is 2.68-2.74.  The cleavage of the aquamarine is indistinct. The crystal system is hexagonal, hexagonal prisms.  The chemical composition is aluminum beryllium silicate.  Transparency is transparent to opaque.

 In his book Gemstones of the World Walter Schumann goes into great depth about aquamarine.  This is where I am getting my information from. The meaning of aquamarine comes from Latin meaning water of the sea.  This is because of the aquamarines seawater colour.  Aquamarines of dark blue are the most desired. Iron is the colouring agent of aquamarine.  Since aquamarine is sensitive to pressure and brittle care must be taken when heating or making jewellery with it.  There are a few trade names out there in regards to aquamarine.  The first one is Santa Maria for really fine aquamarines.  It is so named because of the mine which carries the same name.  This mine is found in Ceara, Brazil.  The second trade name is Santa Maria Africana.  This is for the fine aquamarine that is mined from Mozambique.  It takes its name from the Santa Maria like quality that is found in Brazil.  The third trade name is Maxixe.  The colour of this aquamarine is deep blue beryl.  Since 1917 is has only been found in the Maxixe mine in Minas Gerais, Brazil.  Since the 1970s it is more widely available.  However it has been made more beautiful through irradiation and unfortunately the colour does not last.

The largest aquamarine that was of gemstone quality was found in Marambaya, Minas Gerais in Brazil.  The weight of the stone was 243 lb, was 18 inches long and 15.5 inches in diameter.  This stone was cut up into many different stones with a total weight of over 100,000cts.

In conclusion, I hope everyone enjoyed themselves today learning about aquamarine.  I hope the information that was presented was both enlightening and fun.  Please let me know what you think about this blog or any of the others that have been prepared for you.  I had fun learning about my birthstone and what it is all about.  I would love to hear from you.  Until next time.

The rare gem lady

Beryl Species Part 1 - Emerald

Hi everyone,

I would like to talk to you today about the beryl species.  In this first section I am going to discuss emerald.  I love emerald.  It is one of my favourite gemstones.  I guess I am partial to this stone because of the colour.  I love the colour green so for me there are a great deal of gemstones out there that I just adore.  It reminds me of the spring and summer.  Fresh cut grass and leaves.  Very organic and earthy.  So let's have fun and learn something new about emerald.

The colours of emerald are emerald green, green, slightly yellow-ish green.  The colour streak is white.  The Mohs hardness is 7.5-8.  Density 2.67-2.78 and the cleavage is indistinct.  Crystal system is Hexagonal which is described as three of the four axes are on one plane, are of the same length, and intersect each other at angles of 120 degrees.  The fourth axis, which is a different length, is at right angles to the others.  Typical crystal shapes are hexagonal prisms and pyramids, as well as twelve-sided pyramids, and double pyramids.  This is all found in the book Gemstones of the World by Walter Schumann.  The chemical composition is aluminum beryliium silicate.  The transparency is transparent to opaque.

The name emerald comes from the Greek word smaragdos which means green stone.  Emerald is considered to by the most precious stone in the beryl family.  The green colour of the emerald is incomparable and so by  default is called emerald green.  The colouring agent for emerald is chrome.  Beryls that are coloured by vanadium should be called green beryl not emerald.  Only the finest gemstones are transparent.  The emerald is often cloudy due to inclusions.  The inclusions are not to be considered as faults but proof of natural gemstones instead of synthetic and other imitations.  Some experts refer to the inclusions as jardin, which is French for garden.

One famous emerald piece is in the Viennese treasury is a vase which is 4.5" high and weighing in at 2205cts which was cut from a single emerald.  The biggest emerald ever found was discovered in 1969 and weighed 7,025cts.  The Devonshire Emerald is an other large emerald is 1,383.95cts.

So in conclusion I would like to say that I had a great time talking and learning about emeralds today.  I find it interesting that there is a great deal that we can learn about emeralds and I love learning about the various gemstones out there.  I had fun and I hope you did too.  Please drop me a line and let me know what you think about this or any of the other blogs.  I look forward to hearing from you.  Until next time.

The rare gem lady

Corundum Species Part 2 Sapphire

Hi Everyone,

I would like to continue our conversation with the next type of corundum species which is sapphire.  I hope you will follow me and enjoy our journey through the fascinating world of sapphire.  I like sapphire for the simple fact that it has many shades and colours to it.  It is not what one would call a one hit wonder.  I am especially fond of all the colours but I would have to say I am different in the fact that blue would be my least favourite colour of sapphire.  I really would like to have one day a multicoloured sapphire bracelet.  I find that all the colours together blend so harmoniously and look stunning all arranged to look like a rainbow on your wrist.

So let's talk sapphire.  According to Walter Schumann in the book Gemstones of the World sapphires have the colour blue in various tones, colourless, pink, orange, yellow, green, purple and black.  The sapphire has a Mohs hardness of 9 and the density is 3.95 to 4.03.  The colour streak is white.  There is no cleavage with sapphire which is the same as Ruby.  The crystal system which was explained in the first part of corundum when we discussed the ruby is Trigonal, doubly pointy, barrel shaped, hexagonal pyramids, tabloid shaped.  The composition is aluminum oxide.  The transparency is transparent to opaque.

The name sapphire comes from the Greeks and means blue.  The history of sapphire follows along the same lines as ruby in that in the book Gemstones of the World it is discussed that until 1800 sapphire used to apply to various stones.  Even as far back as the Middle Ages sapphire was understood to mean what is now called lapis lazuli.  In 1800 sapphire and ruby were recognized as corundum, and only at first was blue recognized as sapphire.  Corundums of other colours were given special names which often were misleading.  Some examples that were given in the book are Oriental peridot for the green sapphire and Oriental topaz for the yellow variety.  Today all colours except red are called sapphire.  The red of course being called ruby.  Sapphires are qualified by the description of colour ie: green sapphire, pink sapphire.  The colourless sapphire is called leuko-sapphire which is Greek for white.  There is the rare pinkish orange sapphire called Padparadscha which is Sinhalese for "Lotus Flower".  Mr. Schumann goes on to say, "There is no definite demarcation between ruby and sapphire.  Light red, pink, or violet corundums are usually called sapphires, as in this way they have individual values in comparison with other colours.  If they were grouped as rubies, they would be stones of inferior quality."

The blue sapphires colour agents are iron and titanium, vanadium in violet, a small amount of iron for yellow and green, chromium for pink and vanadium for orange.  The most coveted colour of sapphire is the pure cornflower blue.    Some of the more famous sapphires are the Star of India(536cts) which is considered to be the largest cut star sapphire, which is owned by the American Museum of Natural History in New York.  There is the Midnight Star(116cts), which is a black star sapphire and the Star of Asia(330cts) which is owned by the Smithsonian Institution in Washington, D.C.  Two other famous sapphires, the St.Edward's and the Stuart are part of the English Crown Jewels.

As one can see there is alot we can learn about sapphires.  I hope everyone out there learned something interesting and fun today.  I enjoyed learning about the sapphire and I found it interesting about the famous gems.  Please drop me a line, let me know what you think.  I enjoy hearing from everyone.  Until next time.

The rare gem lady

Corundum Species The Ruby

Hi everyone,

Today I would like to break down the types of gems and talk about each individual species.  The species I am going to discuss and learn about today is the corundum species.  The two categories that fall under this species is Ruby and Sapphire.  The name corundum is originally from India. 

Let's talk about the ruby first.  The colour is varying shades of red.  The colour streak is white.  For those of you who do not know what colour streaking is, it is when the inherent colour of the stone is determined.  This occurs when you scratch the stone on a rough porcelain plate called the streak plate.  The ruby has a Mohs hardness of 9.  It's density is between 3.97 and 4.05  The cleavage is none.  In the book Gemstones of the World by Walter Schumann cleavage is described as "Many gemstones can be split along certain flat planes, which experts call cleavage." The crystal system is (trigonal) hexagonal prisms or tables, rhombohedrons.  In Gemstones of the World this system is described as "Three of the four axes are in the same plane, are of equal length, and intersect each other at angles of 120 degrees.  The fourth axis, which is of different length, is at right angles to the others.  The difference is one of symmetry.  In the trigonal system it is three sided.  Typical crystal forms of the trigonal system are three sided prisms and pyramids, rhombohedra, and scalenohedra.  The chemical composition of the ruby is Aluminum oxide.  Its transparency is transparent to opaque.

Ruby is derived from the Latin word ruber.  The red colour of the ruby is probably what gave the ruby its name.  It was around 1800 that ruby and sapphire were recognized as belonging to the corundum species.  According to Gemstones of the World red spinel and the red garnet were also designated as ruby before 1800.  The most desirable colour for the ruby is called pigeon's blood, which is described as pure red with a hint of blue.  The substance that provides the colour for the ruby is called chromium.  When a ruby is in it rough state the stone appears dull and greasy but when it is cut the luster can rival that of the diamond.  The most common treatment done to rubies is a heat treatment to improve the colour of the gem.  Ruby is known as the hardest mineral after diamond.  Inclusions are common in rubies and do not usually affect quality.  Inclusions typically indicate natural versus synthetic stones.  To have the rare cat's-eye effect and the asterism effect( a six-rayed star) the ruby has to have included rutile needles and the cobochon cut brings out this effect.

a nice example of a star ruby

There have been some famous rubies.  The largest cuttable ruby weighed in a 400cts.  There is the Edwardes Ruby(167cts), which is in the British Museum of Natural History in London, the Rosser Reeves star ruby (138.7cts), located in the Smithsonian Institution in Washington, DC, the peace ruby (43cts) which called this because it was found in 1919 at the end of WW1.  There is also the De Long Star ruby(100cts) in the American Museum of Natural History in New York.  There are rubies in many royal insignia. For example the Bohemian St.Wenzel's crown(Prague) holds a non-faceted ruby of about 250cts.

In conclusion I would like to say that I hope everyone enjoyed reading and learning something new about the Ruby.  I had fun reading and learning new things about the ruby.  I hope to hear form everyone out there interested in this subject.  I would enjoying hearing from you what you thought about this blog or any of the others I have written about.  Please drop me line and let me know what you think.  Until next time.

The rare gem lady