What is cornflower blue?

Image courtesy of Patou / FreeDigitalPhotos.net

Cornflower (image to the right) is a strong light to medium blue flower with a slight violetish tone. Due its beauty its used as a reference point when describing other objects including sapphires.

As you can imagine it is very difficult to define a colour of a natural sapphire by comparing it to a colour of a natural flower. There is no definite mix of colours and cornflowers themselves have slight variations of colour amongst them. Without a doubt colour of a sapphire should be described by its hue, saturation and tone. 

Ceylon sapphires are most famous for their lighter blue colours, and many are close to “cornflower blue”. In the world of sapphires “cornflower blue” is a prestige term and is a highly priced colour. Hence, you see the misuse of this term with some even referring to darker blue sapphires as “cornflower blue”.  

You should always appreciate and love what you see and not the terms used to describe them. In saying that, these terms are still commonly used. If you ever wondered what cornflower blue is, it is more or less a strong light to medium blue with a slight hint of violet. 

Unheated sapphire care and cleaning guide

SUITABLE FOR DAILY WEAR

Corundum (gem material of sapphire and ruby) is the second hardest gem material in the world, second only to diamond, which means sapphire can only be scratched by another sapphire or a diamond. This also means that unlike many other coloured gemstones such as tanzanite, contact with dust (which contains high quantities of silica) will not scratch a sapphire. 

Corundum also has excellent toughness and no cleavage (tougher than diamond). This means that sapphires are not prone to chipping, cracking, or breaking.

Unheated sapphire is also stable under normal wearing conditions such as heat, light, and common chemicals. However, even mild acids like lemon juice can damage fracture-filled and some treated sapphire.

These qualities make natural unheated sapphire a highly durable gemstone suitable for daily wear. 

CLEANING

Easiest and safest way to clean sapphire is to wash it in warm soapy water and wipe it with a gem cleaning cloth. Ultrasonic and steam cleaners are usually safe for untreated sapphires, but you do not need to use chemicals to clean your stone. Due to its hardness sapphire can take a high quality polish and therefore washing in soapy water is more than enough.

STORING SAPPHIRE JEWELLERY

In general, when storing loose gemstones or jewellery, take a good care not to let them touch one another and that each piece is stored separately. As a hard gem material, sapphire can scratch softer gemstones, other sapphires or precious metal such as gold or platinum. And as diamonds are harder than sapphires, it can scratch sapphires. 

This article has been reposted from Deliqa Gems (Copyright 2013 Deliqa Gems) Hope this helps you to look after your precious unheated sapphire. 

Time for transparency?

Recently I had a discussion with a gemmologist who is also a gem supplier and predominantly supplies heat treated sapphires to the Australian market. I’ll try not give you clues of who this person is. 

He/ She says that when he/ she sells a heat treated sapphire to a customer he/ she does not disclose that the stone has been heated unless the customer enquires. His/ Her argument is that as no external elements have been added in the process of heat treatment, the stone is 100% natural and that they have simply sped up the heating process that would have otherwise occurred naturally under the Earth’s surface. He/ She proceeds to say that Australian customers do not tend to query whether the sapphire has been treated, but international customers such as in Europe and US do query this often. 

I believe this has more to do with lack of customer awareness here in Australia, whereas European and US customers are a lot more educated about gemstone enhancements. 

I feel this is a bias opinion from a seller who supplies heated sapphires. Whilst I appreciate that heat treatment has assisted vastly to maintain reasonable prices by increasing sapphire supply in the market, it is still an enhancement to the natural stone. There is no guarantee that a heated sapphire would have the same performance if it was left underground for many thousand years more. One of the greatest fascination of gemstones is their rarity. Evidently fine quality unheated sapphires are rarer than enhanced sapphires. 

Image courtesy of Stuart Miles / FreeDigitalPhotos.net

Customers need to be aware of what they are purchasing. 

In my opinion, if the seller is aware of any kind of enhancement to the gemstone it should be disclosed regardless. The customer can then proceed to ask more questions. This would be a great opportunity for the seller to educate the customer about the difference between traditional heat treatment and other treatment methods. 

We used to deal with heated sapphires ourselves, but we disclosed all information we were aware of. I think it is important to disclose known enhancements of a gemstone and educate customers in order to maintain a trustworthy industry. 

This is such a dividing topic, your opinion is greatly appreciated.