How is Silestone made?

Silestone is a brand of a Spanish Group called Cosentino. The Silestone brand has somehow been associated to the product, and what some call Silestone is in fact an engineered stone. The technology is Italian, from Breton, they have currently about 12 production lines, and have lines specialized per colour. One of the main problems with these plants are the possible contamination that may occur when changing from a dark colour to a light colour, although cleaning is a normal task it's almost impossible to get it 100% clean.
The mixture uses polyester resin, in different proportions it can vary from 7% to 10% (or even more). What establishes the quantity of resin? ... one variable is the grain size of the filler, the bigger the less resin is necessary for a good mix. Besides, resin, they'll use all types of material ... but mainly quartz. Some companies also use silica sand, the advantages are pricing, but it's not as good as quartz. Other components normally used, crushed glass, colouring pigments, other special stones or minerals to give special effects and chemicals to control the cure and the bonding.
The secret of the business is how do they do it, as the technology is wide spread, and basically every Breton plant has more or less the same technical capacity ... now not everyone has a whiter white ...

Compac Quartz & Innovation

Paying attention to the market is one of my main hobbies, and I figure Compac Quartz and all it's secrecy in the factory in Portugal ... has some innovation regarding the whole industry ...
In MHO I think that in the next year or so, their will be an apocalypse in the Quartz based agglomerate business ... with strong price reduction ... Why? Well the Chinese are selling material relatively cheap, and the Euro is getting strong ... so I expect to see more and more Chinese material coming into the market ... even though the European producers don't like it, and try to create barriers ...
Back to the industrial secret, I figure they are exchanging quartz granulates for transparent glass chips ... transparent glass chips has a good behaviour when mixed with other components and it's cheap ... you can get it for less than 0,20€ per kilo ... one sqm of 2 cm slabs weighs about 50kgs (less a bit) ... if 10% is resin ... then you get 5kg x 1,6€/kg=8€ cost for resin ... then you get 45kg of glass x 0,20€= 9€ ... so you get a product costing in theory 17 € raw materials ... now it normally sells in the market to the vanity manufacturer for 50-60€...