While certain granites are tougher than others, ANY granite will survive indefinitely. As a result, your granite memorial should have the same appearance and weight now as it would in 100,000 years or more. Of course, exposure to heat and humidity WILL cause damage to your marker over time, so keep this in mind when choosing a location for it. Also, be sure to include the exact date that you want your stone to represent in the year AD. In general, older markers tend to be heavier and better quality stone than those placed recently. Newer stones may appear white instead of grayish-blue because they are made from lower quality material or even concrete. Even though newer stones are usually cheaper, they do not last as long because there is no gold used in their manufacture like with traditional markers. The life expectancy of a granite marker depends on many factors such as size, weight, type of cut, temperature, humidity, etc. Markers up to about 2 feet (60 cm) high and 4 pounds (1.8 kg) average weigh will last between 50,000 and 200,000 years depending on how they are treated after being placed in the ground. Larger sizes and weights often come with special packaging to avoid damage during transit.