The issue of the use of chalk to bring out lettering on a stone can be a touchy one, sometimes just as much as the use of shaving cream. And just like shaving cream, there is a lot of just plain wrong information on the internet and in other resources. So before I said anything one way or the other, I did some research on the question to find out what true experts on the subject had to say, and followed up with some experiments to confirm. I figured that the best place to start was by contacting Crayola and asking them if they felt that the use of chalk on stones was safe for the stone itslef. Here's what they had to say: "Crayola sidewalk chalk contains plaster of paris which has a gritty texture. Plaster of paris is not considered to be biodegradable, nor are most of the pigments contained in Crayola sidewalk chalk. Also, product packaging warns of colorants that may stain. This could be a good factor depending on the exact nature of what you are trying to do. While packaging does warn of colorants that may stain, chalk used outside generally washes away because of extreme weather conditions and excessive rain. Again, this could vary depending on the surface it is applied to." If you look on their website, you can find the following additional information: "Molded chalk, such as Crayola Colored chalk, is a softer chalk, made of plaster of Paris, which is defined as quick-setting gypsum plaster consisting of a fine, white powder, calcium sulfate hemihydrate, which hardens when moistened and allowed to dry. Sidewalk chalk is much harder than regular chalk; in fact, will actually scratch a typical chalkboard." I decided to test that last statement out so I went out and bought 6 different brands of sidewalk chalk, and 4 brands of regular. I took them up to our Church where they had some old slate blackboards that they were no longer using and conduced a test. Sure enough, all 6 brands of sidewalk chalk left scratch marks on the board. As did 2 of the regular type chalks. From what I've seen, most people that use chalk tend to use the sidewalk type because it's much larger than regular. As mentioned above from the Crayola website, chalk is made from plaster of Paris. According to A Dictionary of Science, Oxford University Press, © Market House Books Ltd 1999, "The hemihydrate of calcium sulphate, 2CaSO4.H2O, prepared by heating the mineral gypsum. When ground to a fine powder and mixed with water, plaster of Paris sets hard, forming interlocking crystals of gypsum. The setting results in an increase in volume and so the plaster fits tightly into a mould. It is used in pottery making, as a cast for setting broken bones, and as a constituent of the plaster used in the building industry." So according to that statement, chalk if left on a stone could set and harden into something that could cause damage to the stone, by seaping into and filling up and expanding, anc causing the potential to crack or break the stone. William Spurlock Saving Graves http://www.savinggraves.com ----- Original Message ----- From: Debby Beheler To: INPCRP-L@rootsweb.com Sent: Sunday, September 30, 2001 8:25 PM Subject: [INPCRP] Chalk I hope someone will enlighten us to the damage chalk causes. I am an advocate of using chalk to bring out the inscription, esp. when all else fails. It seems to me that if it is the only way to read the stone, at least we have preserved the information contained there when there may be no way to read it in a few years. I have been carrying a spray bottle of plain water with me to rinse the chalk off afterwards. I am, however, willing to listen to the reasons not to use chalk. Debby Beheler __________________________________________________ Do You Yahoo!? Listen to your Yahoo! Mail messages from any phone. http://phone.yahoo.com ==== INPCRP Mailing List ==== If you know of some good cemetery related links, send them to LoisMauk@usa.net.

William, Well done and well said! Scott -----Original Message----- From: William Spurlock [mailto:wspurlock@savinggraves.com] Sent: Sunday, September 30, 2001 8:59 PM To: INPCRP-L@rootsweb.com Subject: Re: [INPCRP] Chalk The issue of the use of chalk to bring out lettering on a stone can be a touchy one, sometimes just as much as the use of shaving cream. And just like shaving cream, there is a lot of just plain wrong information on the internet and in other resources. So before I said anything one way or the other, I did some research on the question to find out what true experts on the subject had to say, and followed up with some experiments to confirm. I figured that the best place to start was by contacting Crayola and asking them if they felt that the use of chalk on stones was safe for the stone itslef. Here's what they had to say: "Crayola sidewalk chalk contains plaster of paris which has a gritty texture. Plaster of paris is not considered to be biodegradable, nor are most of the pigments contained in Crayola sidewalk chalk. Also, product packaging warns of colorants that may stain. This could be a good factor depending on the exact nature of what you are trying to do. While packaging does warn of colorants that may stain, chalk used outside generally washes away because of extreme weather conditions and excessive rain. Again, this could vary depending on the surface it is applied to." If you look on their website, you can find the following additional information: "Molded chalk, such as Crayola Colored chalk, is a softer chalk, made of plaster of Paris, which is defined as quick-setting gypsum plaster consisting of a fine, white powder, calcium sulfate hemihydrate, which hardens when moistened and allowed to dry. Sidewalk chalk is much harder than regular chalk; in fact, will actually scratch a typical chalkboard." I decided to test that last statement out so I went out and bought 6 different brands of sidewalk chalk, and 4 brands of regular. I took them up to our Church where they had some old slate blackboards that they were no longer using and conduced a test. Sure enough, all 6 brands of sidewalk chalk left scratch marks on the board. As did 2 of the regular type chalks. >From what I've seen, most people that use chalk tend to use the sidewalk type because it's much larger than regular. As mentioned above from the Crayola website, chalk is made from plaster of Paris. According to A Dictionary of Science, Oxford University Press, © Market House Books Ltd 1999, "The hemihydrate of calcium sulphate, 2CaSO4.H2O, prepared by heating the mineral gypsum. When ground to a fine powder and mixed with water, plaster of Paris sets hard, forming interlocking crystals of gypsum. The setting results in an increase in volume and so the plaster fits tightly into a mould. It is used in pottery making, as a cast for setting broken bones, and as a constituent of the plaster used in the building industry." So according to that statement, chalk if left on a stone could set and harden into something that could cause damage to the stone, by seaping into and filling up and expanding, anc causing the potential to crack or break the stone. William Spurlock Saving Graves http://www.savinggraves.com ----- Original Message ----- From: Debby Beheler To: INPCRP-L@rootsweb.com Sent: Sunday, September 30, 2001 8:25 PM Subject: [INPCRP] Chalk I hope someone will enlighten us to the damage chalk causes. I am an advocate of using chalk to bring out the inscription, esp. when all else fails. It seems to me that if it is the only way to read the stone, at least we have preserved the information contained there when there may be no way to read it in a few years. I have been carrying a spray bottle of plain water with me to rinse the chalk off afterwards. I am, however, willing to listen to the reasons not to use chalk. Debby Beheler __________________________________________________ Do You Yahoo!? Listen to your Yahoo! Mail messages from any phone. http://phone.yahoo.com ==== INPCRP Mailing List ==== If you know of some good cemetery related links, send them to LoisMauk@usa.net. ==== INPCRP Mailing List ==== This list is for discussion of topics related to the Indiana Pioneer Cemeteries Restoration Project only.