Stone 101 - Education Information

Information is always educational, but when it comes to stone it can be very hard to get.

Most people want information and can’t get enough of it; this is the way I am. I spend what little money I have buying information from all over the world; from modern to books dating back to the mid nineteenth century, or older, if I can find them. Perhaps I can’t speak the language, yet information on stone sometimes is a universal language of its own.

Finding information on stone and which one to choose is always a main concern. Then once you think the color and stone is right, getting information on the historical data or ASTM testing and quarry information becomes a problem, especially when people keep changing the names. Evaluating the quarries is a major concern on large jobs or with stones that have problems or limited availability. Perhaps information is a budget on the installation or the cost of the stone. Gather information on how the stone is made or find all data on the factory that will make the stone, and if they are able and capable, and have the quality controls you require.

I like to know all the information there is on a stone, and whether to recommend it or not and how does it stand up for the application in question or its durability. Historic test data is helpful, but data that is over 5 years old is not up to date. Even data taken from one quarry of the same stone is not the same as the data from a nearby quarry. It can vary a lot, and even within the quarry itself. Some quarries are red on one wall; turn 90 degrees and the stone is brown. Rosa Porrinho can vary in the quarry, and from quarry to quarry The test data for a sample could be a compressive strength of 1300 psi at one quarry which fails, and 1800 at another; that is a large variation.

Sometimes a stone can be so consistent in color and veining, and some stones are unique to each block. Other times it is when it was quarried, as for example Crema Marfil today does not match that same selection of 30 years ago. You can go to one distributor and see this stone and then go to another and the selection and range will be different since there are different quarries and different producers, each grading their own production, and there is not a universal standard for selection and sorting of stone. Some think granite is all consistent, but it is not. There is grading of this stone, as well as the various marble classifications of marble, such as A, B, C, and D.

Getting information on your quarry is just as important as gathering information on the company producing your stone, as company quality and selection controls vary just like the type of equipment they use to produce it. Get references on your producer or fabricator, have someone visit and inspect the facility. Compare their work with that of other producers and find out how reliable and on time they really are. Most companies don’t offer a warranty or guarantee so always read the fine print.

Knowing the variation and natural issues of a stone, and being knowledgeable and seeing large samples, slabs, blocks of the stone up close can tell you a lot. Though the stone may have pits and small fissures that are resinated, it is common today to see along with mesh backing, glued-up marble that has been repaired, veining changes, color changes, and many other issues. The key is to know all about the stone and see large samples, and have a professional explain the stone even better. In the long run, the more knowledge you have of the product, the better chance you will have of not being surprised or disappointed, or at least knowing how to deal with the issues.

So many people have said “if I had only been told or known about the issues, I could have” watched more closely, or selected another  stone, or put the problem stones in the closets and back hallways, or paid extra to have more stone delivered and reject the worst and so on. Don’t depend on photos to show you the true color of the stone. Know the finishes of the stones, and what stones are capable of taking what finish and how that affects the color and character of the stone. Get the prices cut to size to your measurements and know the installation costs and ask for alternates if they are available and compare. Look at domestically fabricated stone versus always looking at foreign produced stone, but know where it comes from in all cases.

Most sales people or persons involved in helping you with the stone don’t know the issues and are not well educated themselves. Most have never been to a quarry or visited a foreign producer, and many times don’t even know the real name of the stone or its origins. Get the facts and get educated. Don’t accept half of the information, or pick a stone based on color only after seeing a six inch sample.