Granite rejection procedure/check list of acceptance

[Krishna22]

Granite rejection procedure/check list of acceptance?
If available please share with me immediate requirement.....plz
Due black spot client are rejected the granite is true any reference?? (coco brown polish)

 

[Dnyan Deshmukh]

Hello Krishna, Granites are natural product and made by slicing a rock / stones slabs.

as its a natural product, there is no guarantee of similar slabs or uniformity in the textures we see on it.

Acceptance and Rejections is solely dependent on the mutual agreement between supplier and purchaser for what is acceptable.

Granites when viewed under shade, in light and at different angles may give a different looks.

The surface texture requirement is mostly an aesthetic issue and should be reviewed by Architect or a Person who did finalization of stones.

There is as such no criteria for acceptance or rejection of granite base on its surface texture.

 

[amd007]

Agree with Dnyan, however as you need rejection or acceptance criteria, then I would suggest you the following:

1. Check the density of the granite slab by weighing a sample or a slab and see that the density is approx 2691 kg/cum which is the first indicator that the granite is of good quality.
2. Check the thickness of the granite is it within the range that you have specified generally for countertops we use 25mm thick and so on.
3. Check the visual appearance take a close look at granite to see if you notice any dings, dents, scratches or uneven surfaces. Even baby cracks can turn into large cracks with the potential to snap the entire slab in half during or after installation.
4. Check the porosity of the granite, There’s a little test you can do to determine porosity. Grab a lemon and squeeze a drop of juice onto the countertop surface. Watch it to determine how long it takes to absorb. If it takes a long time or doesn’t appear to be absorbed at all, that means granite is less porous, requires less sealant and will last longer. On the other hand, if the juice absorbs rather quickly, granite is very porous and will need regular coats of sealant to survive.
5. Check the granite polish quality- Check the quality of granite polish by using metallic materials to scratch at the surface. If metallic materials leave behind a mark, the polishing was not done to the highest quality and will not withstand day-to-day use.
6. Finally, You can identify granite from marble and other types of stone by using the scratch test. Use a knife blade to try and make a scratch on the surface make sure to use surface which will be out of sight so that the full slab is not spoilt. If it’s difficult to make any mark on the surface, you’re likely looking at granite—or some type of igneous rock. If the surface does scratch, you’re likely looking at marble or limestone.
7. Happy Testing.

Note : Generally at site we first approve a sample, based on the sample approved we check with the vendor how much quantity is available, if its within our requirements then we plan a visit to the vendors godown and check the lot there, have a joint inspection, then sign the total consignment and only that quantity is delivered at site, the signatures are again verified at site and only then downloaded. This is generally done for large consignments based on our priorities.

 

[Gnyoganarasimhan]

One more thing to be tested
Two types of cutting
Kerosene cutting Though it is not being used nowadays

 

[kulkarni]

pour water on the surface and check hair cracks. There should not visible cracks