The original quarry that Absolute Black granite came from was from South Africa. That granite was so dense the granite didn't need to be sealed to protect it from staining.
In recent years Absolute Black granite has become very popular and China and some other countries started exporting Absolute Black granite unfortunately in many cases it's not the same dense Absolute Black granite that was coming from South Africa. The Absolute Black granite that has been coming from other countries is dense granite but in many cases isn't really black but a gray calcite based stone such as marble that will etch like marble leaving gray rings and spots should acidic liquids come in contact with the stone. Many have dyed these gray stones to make the stone black or more black.
To be assured you are purchasing a true Absolute Black granite all you need to do is a simple test by pouring a little bit of lemon juice onto the Absolute Black granite and should it turn gray the stone is not a true Absolute Black Granite. In most cases it's not the fault of the slab yard or granite fabricator because many believe they purchased a true Absolute Black granite and have no idea the stone was dyed. If you have an Absolute Black granite that you do believe is a dyed Absolute Black granite you need to protect it the best you can keeping it very repellent so should acidic liquids come in contact with your stone it will repel the liquid for a period of time before leaving gray rings and spots. It's a personal choice you may even like the appearance of the Absolute Black granite even if it may be a dyed stone. The Granite Shield process on calcite based stones will not prevent surface etching but will reduce it about 80%. Acidic liquids, alcohol and vinegar can etch Absolute Black granite that has been dyed, marble, travertine and limestone if left unattended on your stone surface. Water with a lower pH level lower than 7 is considered acidic.
pH Values
Stomach acid 1 to 3
Lime Juice - 1.8 to 2
Lemon Juice - 2.3
Coca Cola - 2.5
Soft drinks - 2.5 to 3.0
Vinegar - 2.4 to 3.4
Apple Juice - 3
Orange Juice - 3.5
White wine - 3.0 to 3.3
Red wine - 3.3 to 3.5
Drinking alcohol such as gin, rum and vodka - 3 to 6 adding Orange or Lime juice will lower pH
Tomato & Tomato Juice - 4.2
Beer - 4.5
Coffee - 5.5
Normal rain - 5.7
Milk - 6.2
Saliva - 6.3 - 6.6
Dog urine - healthy is 6.2 to 6.5
Drinking water - 6.5 to 8
Water - Under 7 is considered acidic
There is currently no penetrating sealer that can stop etching on calcite based stones. On what is believed to be Absolute Black granite etching may accure that leaves gray rings and spots on the surface. A topical sealer is not recommended for natural stone because it blocks the pores of the natural stone then can't breathe and the top coating can scratch easy. So what happens to natural stone that can't breathe? Moisture gets trapped and can cause a chemical and mineralogical change within the stone. This action of decay in natural stone may take form of pitting, spalling, flaking and oxidation.
On polished granite the granite gets smoother and shinier. On honed granite the Granite Shield for honed stones does not make the honed stone shinier.
Granite Shield is a national and international sealing service providing customer leads to authorized Granite Shield applicators.
Applicators and granite fabricators are independent contractors and businesses and are not employees of the Granite Shield corporate office.
Copyright 2012. All rights reserved. Granite Shield is a registered trademark.
Kleen N Shine, Kleen N Seal, Kleen N Shield, Granite Kleen, MicroArmor, Silicabright, Pro-Armor, Pro-Premier, Crystasheen, Armor, Nustone Kleen, Premier, Ultra Seal, Stone Shield, Krete Shield is a trademark and/or registered trademark of Granite Shield.
