I have a glazed ceramic pot in the garden that has a hard white lumps appearing on it , it may be coming from inside . I have tried removing it with heavy duty cleaners but no success. Any ideas?
Porcelain
Porcelain
try white vinegar
Since it is a hard ceramic, it is not prone to staining by normal foods and normal cooking. There is a notable exception, however, involving iron and cast iron. Contact with either of these can cause unsightly brown stains that are impossible to remove.
The description matches that of porcelain, a type of ceramic made from fine clay. Porcelain is known for its durability, whiteness, and translucency, making it a popular material for dishes, vases, and decorative items.
Porcelain is a hard, white, translucent ceramic made by firing a pure clay and then glazing with variously colored fusible materials; china.
Ceramic
To effectively remove white residue left by hard water, you can use a mixture of vinegar and water to clean the affected area. The acidic properties of vinegar help to dissolve and remove the mineral deposits that cause the white residue. Simply spray or apply the vinegar solution onto the surface, let it sit for a few minutes, and then scrub or wipe it away. Repeat the process as needed until the white residue is completely removed.
Ceramic tiles are made of clay baked in a kiln and hardened through extremely high temperatures. This makes for a very durable tile with an extremely hard glaze. The tiles Ceramic surface has a low porosity. Because of this, dirt doesn't cling well. This makes ceramic tile easier to clean. It is forgiving too. Because it is so hard, occasional abrasive cleaning is all right and the surface will come out shining. Because of these reasons when installed correctly Ceramic tiles can last the lifetime of a home.
Try white vinegar, or WD40, or lemon juice, or sunscreen.
If the skin is hard, white, and developes blisters, frostbite is most likely.
An extremely hard one. I would be tempted to drive it out with a very hard pin punch.