Tanzanite: Simulants and Treatments

Tanzanite is best known as the transparent Blue-Violet variety of Zoisite. It has, up until the date of writing, only been mined in the Manyara Region of Tanzania (hence the name ‘Tanzanite’), near the Merelani Hills where it was discovered in 1968. Read More…

by Kaylan Khourie, FGA

Fancy Coloured Diamonds

Coloured diamonds are rare
gems found in every colour
imaginable. Each colour has a different cause and can be created naturally during growth underground or via laboratory treatments. Laboratory-grown diamonds
can also be grown as specific colours or treated post-growth to create the desired colour. Read more…

By Kaylan Khourie

HPHT and CVD Laboratory-grown Diamonds. What’s the difference?

Gem-quality laboratory-grown diamonds have become fairly popular as an option for jewellery in the past few years and have recently become more available in South Africa. This is probably due to the lower prices and wider availability – due to large factories1 constantly growing many diamonds in all shapes, sizes and colours2 – compared to natural diamonds. Read more…

By Kaylan Khourie

What are Synthetic Diamonds?

A diamond is a mineral made up of essentially crystallized carbon. They occur naturally and can be grown in a laboratory using two methods: High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD). Both methods imitate the environment within which natural diamonds grow, in order to grow diamond onto a seed plate (made of a thin slice of diamond – either natural or synthetic). Read more…

Got a pocket full of Sunstone? Maybe think twice

There are gems being marketed as “Sunstone” in the industry. However, these are frequently just pieces of glass containing tiny copper inclusions. The correct name for this is “Aventurine Glass” – however the misnomer “Goldstone” is more popular for marketing purposes. Want to familiarise yourself with the differences and learn more about Sunstone? Read more…