Cryptocrystallines like agates are more often opaque. Agates and Cryptocrystallines can be slightly softer than Macrocrystallines, 6.5 on Moh’s scale rather than a full 7.
Cryptocrystallines have a duller, wax-like luster while Microcrystallines have a shiny, vitreous luster.
Cryptocrystallines have a higher water content as well as other non-quartz ingredients, up to 20% more.
Because the Cryptocrystalline Quartz can include several Non-Quartz minerals, many of these Quartz are considered Rocks.
Macrocrystalline Quartz– like. Amethyst, Citrine, Tigereye, and Smoky Quartz, which are more likely called Gems, Gemstones or “stone due to their Purity, Bling, shine.
Cryptocrystalline Quartz can look like a Coloured Rock or a dirty rock until it is broken, smashed or cut open. Picking one up, the colours get your attention. Check out Agate. Lots of beautiful colours.
These are my Agate From Agate Creek in Qld.
Agate come in lots of colours have a look at these agate pictures . Are they Real?
Citrine is the yellow to red-orange variety of crystalline quartz. Image of Citrine Colours.
Majority of Citrine on the market is produced by heating smoky quartz (which produces light to medium yellows,and Amethyst (which produces stronger yellows and orange-red to orangey brown shades).
Due to its abundance, it would “get no respect,” as it were. In recent decades this perception has changed, due in part to fashions that emphasize earth tones. Home shopping networks have been marketing the various shades of Citrine aggressively with catchy adjectives like “butterscotch” and “whiskey.
Very little Citrine is actually mined. The vast majority of Citrine on the market is produced by heating smoky quartz (which produces light to medium yellows) and Amethyst (which produces stronger yellows and orange-red to orangey brown shades). Natural stones tend to be pale yellow, often with smoky tones. Citrines range from light, lemon yellow to a rich, orange colour with red flashes referred to as “Madeira.” (This refers strictly to a Citrine colour, not a locality, and is an accepted description. However, the use of the term “Madeira topaz” to refer to Citrine is incorrect).
Citrine’s yellow colours are due to the presence of ferric iron. These colours have been traditionally associated with topaz.
Confusion between these gemstones does occur, even though quartz and topaz are distinct gem species.
Unfortunately, this is a common story. A little history will explain why. Before the 20th century, all gems in the brown, orange, and yellow color range were called topaz. Modern gemology was only recognized as a science in the 1930s. Now, we recognize topaz and yellow or brown quartz as separate species. However, many jewellers have continued to use the old names. For example, “smoky topaz” is much more likely to be smoky quartz than brown topaz.
Citrine gemstones (yellow quartz) are less frequently confused with topaz gemstones, but it does happen.
Quartz and topaz are different gem species. They’re composed of different chemicals and have different physical and optical properties. They’re also valued very differently. The quartz family of gems is much more common than topaz. So even though they may appear similar, the more common quartz varieties are less valuable than topaz. Despite what your appraiser told you, topaz and citrine gemstones are definitely not “basically the same.” (See our List of False and Misleading Gemstone Names for more examples of quartz referred to commercially as varieties of topaz).
Some jewellers can perform accurate appraisals. Others cannot. Consumers need to be aware that there are no qualifications or regulations for writing a gemstone appraisal. To protect your investment, contact an independent gemology lab that specializes in identification and appraisal.
Citrine makes a fine jewelry stone. With no gemstone cleavage, a hardness of 7, stable colors in light, and no special care requirements, it can be used for any jewelry application. Like most quartz, it’s available in large sizes, so custom gem cutters can use this stone for dramatic and intricate cuts. This gem is a wonderful option for a large, beautiful stone for an engagement ring. Citrines can also be used for carvings.
At the top end of the scale are prime specimens of the most saturated yellow, orange, and reddish tones. Those with less intense colour fall into lower value ranges, with pale or smoky stones at the bottom. As with any gem material, custom cutting increases value. Inclusions decrease it. There is no exponential increase in value per carat with increase in size, as larger sizes are readily available. In many fancy cut or carved specimens, most of the value is due to the artistry of the cutting.
Citrines can be grown hydrothermally in labs. Although natural quartz is common and inexpensive, synthetic quartz can be manufactured in sufficient quantities and at low cost, which makes the practice economically viable.
Turning natural smoky quartz and amethyst to Citrine via heat treatment is usually done right at the mine. This is a stable treatment and is fully accepted within the gem trade. Colourless quartz stones have also been irradiated and heated to produce a neon, slightly greenish yellow colour. These stones are called lemon quartz.
The prized “Madeira” colour is created by heat treating Citrine that possesses the proper iron content. Since there is no simple way of testing the iron content of Citrine, this process must be monitored carefully.
Virtually all natural Citrines come from Brazil.
Citrines in the thousands of carats are known. The Smithsonian Institution (Washington, D.C.) has Brazilian stones of 2,258, 1,180, 783, 278, 265, and 217 carats. Most large museums have similar baubles.
Is a Variety of
1.544 – 1.553
Yellow to Red-Orange
Conchoidal, very brittle
2.651 (very constant)
Amethyst can be heat treated to change it to citrine. Not common. “Madeira” citrine with red flashes is a result of heat treatment.
Very weak, different shades of yellow or orange.
o = 1.544; e = 1.553 (very constant). Uniaxial (+)
From the old French citrin, meaning yellow.
Generally in pegmatites and veins. Found in geodes in alluvial deposits.
Natural quartz stones, including citrine, may have liquid, bread crumbs, zebra stripes, two and three phase inclusions, and negative crystals
I have found Citrine where there is lots of Amethyst. Now that I have did this post, I understand that what I have is yellow Quartz. Heat treated buy the sun. In the same area, there is green amethyst. So with long exposer to the sun can colour your Quartz Gemstone.
Yellow topaz, I have not found, Clear I have. There is a big different to Quartz, Topaz has 8 sides and is like clear glass, very clean glass, like it has already been polished. Topaz you find up the creek, that has been wash buy the sand is different again, it is rounded and is not clear.
In June 2018 we are going to go to Gemtree to find Citrine. read more later this year, about this gemstone.
I hope your have found this interesting about citrine.