The word transparent in English explains the allowing of light passage from one end to another end.
The same way in gemstones,
transparency is the allowing of light from one side of the gemstone to another end of the gemstone.
In the gemstone transparency there are three major terminologies used or words used. Failure to know the three can make you see something else on the web, and once it reaches you, it will look different from the way you saw it on the web. It is not that you have been cheated but you did not know the terminology used.
These words can be found frequently used in the websites that sell gemstones, and it is good to know what they mean otherwise you will receive gem quality from website that you don’t expect t.
These are the gemstones that have the ability to allow light to pass through. A good example is a glass the way it allows the light to pass through from one end to another end. Facet cut is more applicable if gem is transparent and in market can command high prices.
If you see in the website or seller says the stone is transparent that means the light can penetrate from one site to another side of the stone.
Take note here, the stones can be transparent and same time can have visible inclusions. So transparent gem and gems that have inclusions knowing that there are different two things
These have a way of spreading light (light diffusion), light goes in the gemstone but is not allowed to pass the other end. To know and identify this kind you must be skilled or else go for courses on how to identify translucent gemstones.
These don’t allow light to pass through to the other end of the gemstone. Is like a piece of wood.
A good example are
black tourmaline or
So when you come across a sapphire or a ruby called opaque sapphire or opaque ruby, then you should know this one does not allow light to penetrate by any means. Gem cutters prefer to cut cabochon style if gem is opaque