CITRINE QUARTZ. TREATMENTS AND SYSTHESISThe citrine is a gemological variety of the Quarz. It’s habitual color is yellow or yellowish. Also , though most infrequent, from orange to red.
1. THERMAL TREATMENTSSome Quartz subjected to heat may take the citrine’s colour. In concrete the amethyst with presence of Iron (Fe) need only temperatures higher than 450 Celsius degrees and lower that 600. The process is simple and doesn’t require any additives of any kind. It’s at every amateur reach of hand. The smoked quartz also allow a very similar treatment.
It’s used to treat small or medium size gemstones. Big models, of more than 100 carats, have never seen them heated, they are more complicated and hard to manipulate.
The procedure it’s considered a non aggressive treatment and it’s authorized by the CIBJO and practically all the institutes and gemmological laboratories around the World. At a professional level, it’s totally allowed and admitted the citrine’s heat treatment.
Also, there is no reliable way of detecting these treatments in Quartz. It’s almost impossible. Due to this, the laboratories don’t use to pronounce themselves about this subject, or just do it without compromising. Just some colours, orange and reddish, if are too vivid and obvious, may rise suspects about manipulation. But, we insist, it almost impossible to have a total certainty. Besides, the heat, may always be produce in nature, in very ancient geologic stages.
Just some physics laboratories leader in Europe may resolve doubts about heated Quartz. Although, the prices of these analysis are prohibitive, out of place and the warranty of certainty is, for the moment, doubtful. Due to this, these exams are not used in gemmology,
Due to all this, Citrines have exactly the SAME PRICE, heated or not. This subject is not commented in any auction or jewellery of the world. The data about this particularity are just ommited.
Most of the Citrines that we offer are from Brazil. Our gemmologists there, procure to acquire materials from well known, trustful mines. They reject the uncut and gems that, by their colours, have been evidentially manipulated. We realize periodic monitoring in the production places to have the certainty that the original uncut pieces are correct. Due to this when we offer Citrines we indicate, beside the country of precedence, the name of the town and the mine. This is a very important detail for the identification of all the precious stones, because it allowed us to know fundamental elements for the classification. It’s vital information for almost all gemstones, and essential in case of the Citrines.
Our firm has stationed in Brazil, in a permanent form, a gemmologist that, from many years ago cover all most important miner places, and let us know all the news and changes. In this way, our information it’s always updated and allowed us to go ahead. Our interested buyers may request further information about the origin and the characteristic of the mines of reference. We’ll gladly give you this information.
We will like to remind you that some mines are mythic, producers of natural Citrines, providers of our enterprise. In first place, all those that belongs to the Coronel Murta (M.G.) area, Gavilao, Lorena, Morro Redondo, Serrinha, Páu Alto, etc. All there are famous by the quality of their products. In Brazil there are about 1000 active mines from which natural Citrine is extracted.
Vipscollection seeks to offer natural Citrines. And our experience of decades in the jewellery sector is applied rigorously. We buy and sell this gemstones when we believe are natural. And only then. Until now, in almost 40 years of commerce around the world, we haven’t had any complain about this.
Due to all this and the policies we have expose, allow us affirming that our Citrines are natural, without any treatment or manipulation. 100% Natural.
2. IRRADIATIONAre not frequent but they exist. Some Morión Quartz (black) or very dark smoked are the result of these practices.
Also some Pink Quarts have an altered colour due to this treatments.
By irradiation the Prasiolites (green, very abundant) are obtained and the yellow-green Citrines. Also (though no very common) the Cognac and orange tones.
The “Fantasy” colours: green, blue, and other that doesn’t exist in nature, are all products of irradiation.
We consider that these materials may not be sold without advertising it clearly. The opposite will be the a lack of ethic. Irradiated material has no economical value.
3. SYNTHESISThere are synthesis of the Quartz in almost all their gemmological varieties. From the 80’s have been commercialized in bid quantities. Nowadays the main consumer of this product is China. Most of the Quartz that is offered to the world is synthetic.
The synthetic quartz it’s obtained by heat or irradiation, or both combined, to get Amethysts, Citrines, Prasiolites, Ametrines and other varieties. Also fantasy colours.
We firmly relieve that the misleading sale of this material is a public fraud. The synthetic materials have no economical value.
This essay has been written by Vipscollection’s gemmological team. It’s a brief resume in which we have only touched very few concepts.
This document has been written in Spanish. Due to this there might be some translation mistakes. We offer a copy of the original for who ever might be interested.