The only quartz that I have ever seen crack was one where painters stood on a sink rail to paint. In other words,abuse. I'd bet that was the issue where as well.

There are a few blogs/writers on the internet who have posted their problems with cracks and Silestone. A quick "google" search will bring up several people's concerns with this very issue. There are repair kits for Silestone cracks...so there is obviously a need for these things.

Silestone and Quartz are extremely durable. It seems like there was some sort of abuse there. Also, make sure you are getting 3cm thickness. I know some fabricators out here give people an amazing price for quartz- and it ends up being 2cm [thinner than what we quote]. The thickness will definitely effect it's strength for sure. Especially when holes are cut into it.

Thank you Sophie Wheeler, Cancork & DirectSinks for your comments. I'm still working on my problem. As expected Silestone, the supplier & the fabricator are placing blame entirely on the installer. We saw the installation; it was done very carefully and we saw no sign of abuse from time of delivery thru installation. Given that the crack is on both sides of the hot water faucet, I can't help but wonder if there was damage during fabrication (when I googled "cracks" I found that this can happen around faucet drill holes if heat from drilling isn't controlled), or if the extremely cold temperature in January/February had any effect. As it stands right now I and/or the installer have to pay for another top. As a courtesy to the supplier (not me!) the fabricator has offered a 10% discount on the replacement which won't even cover sales tax & delivery!). I want to look more into repair option. The more visible crack in front of the faucet is hairline - the one behind the faucet is more noticeable tho' hidden somewhat by the height of the faucet. My installer has a picture which I want to obtain and will post. If I buy another it will be from a different fabricator - ideally one who will install it and guarantee their product thru installation. This is a 31.5 x 22.5 (Lagoon) top - I don't know if a local (Long Island, NY) fabricator would install. I'm going to request drawing from supplier and look into this. Thanks again to all............

We are located on Long Island, NY and work/sell to a lot of fabricators. But I'm not sure what a "lagoon top" is... is that a material? color?

Lagoon is the Silestone color

We work with a couple of fabricators that we trust to install Silestone. If you want us to quote it for you, just message me your information and we will have a designer contact you for all necessary information we will need.
- Karly

Sounds like my issue - 3.5 feet is quite a distance to think that yours cracked from uncontrolled drill hole heat. I am still living with my cracked Silestone top and very unhappy about it. I would certainly choose another material if I replace it or undertake another project.