I’ve posted a few entries now relating to metal and I’ll be posting many more! This time though, I’d like to take a little detour and talk about another integral part of jewellery making; gemstones and lapidary. This subject is just as extensive as that of metal, if not more so. Although you don’t need to be an expert in gemology to make jewellery, you should have a basic understanding. Believe me, it will come in handy when choosing your settings or cleaning your pieces. It will also give you an advantage when buying gems, as you may have an idea as to what’s legitimate and what’s a scam. Of course, if you’re like me, you’ll grow to appreciate the beauty of the many different kinds of stones and minerals. You’ll want to learn to cut and polish your own stones and maybe end up with a collection. My suggestion is to find out if there are any lapidary clubs in your area, and join up! That’s how I got started.
First things first, this post will give you a a basic rundown of some of the terminology you’ll run across, and an understanding of how stones are identified, graded and enhanced.
First things first, this post will give you a a basic rundown of some of the terminology you’ll run across, and an understanding of how stones are identified, graded and enhanced.
Lapidary
If you haven’t already guessed, lapidary is the art of cutting gems and can also refer to the artist who cuts gems. Cabochons, beads, faceted or carved, it’s all lapidary work.
If you haven’t already guessed, lapidary is the art of cutting gems and can also refer to the artist who cuts gems. Cabochons, beads, faceted or carved, it’s all lapidary work.
Mohs Scale of Hardness
Developed by German mineralogist Friedrich Mohs in the early 19th century, this scale rates the hardness of a stone or mineral from 1 (very soft) to 10 (very hard). The hardness of a sample is determined by finding the hardest material the sample can scratch or conversely, by finding the softest material that can scratch the sample. There are several reference points used; fingernail, Mohs 2.5, copper penny, Mohs 3, pocket knife, Mohs 5, glass, Mohs 5.5-6, steel file, Mohs 6.5 and diamond, Mohs 10. Also keep in mind that each classification can be scratched by the ones above it, or can scratch the one below it. So a Mohs 4 can be scratched by a Mohs 5-10 and can scratch a Mohs 1-3. Here’s a chart with some examples:
Developed by German mineralogist Friedrich Mohs in the early 19th century, this scale rates the hardness of a stone or mineral from 1 (very soft) to 10 (very hard). The hardness of a sample is determined by finding the hardest material the sample can scratch or conversely, by finding the softest material that can scratch the sample. There are several reference points used; fingernail, Mohs 2.5, copper penny, Mohs 3, pocket knife, Mohs 5, glass, Mohs 5.5-6, steel file, Mohs 6.5 and diamond, Mohs 10. Also keep in mind that each classification can be scratched by the ones above it, or can scratch the one below it. So a Mohs 4 can be scratched by a Mohs 5-10 and can scratch a Mohs 1-3. Here’s a chart with some examples:
Mohs # | Common Object Test | Mineral |
Knowing the hardness of a stone helps determine what use the stone is best suited for, jewellery, carving, faceting, etc. Also bear in mind that softer stones are more suited for pendants or earrings. Stones in rings and bracelets are subjected to more wear and tear. Hardness may also affect which method you chose for cleaning or polishing your pieces.
Stones for jewellery come in different forms. Beads, tumbled stones, carved stones, cabochons and faceted stones are the most common.
Beads can be any shape or size but all have at least one hole drilled through for stringing.
Tumbled stones are rocks of varying shapes and sizes that have been smoothed and polished in a tumbler. The rough stones are put in a tumbler barrel with water and a polishing grit and the barrel is placed on a machine that will rotate the barrel non stop. There are at least four grits, coarse, medium, fine and polish, and the stones are usually tumbled non stop for at least one week per grit. So that pretty pile of polished pebbles has taken a month to produce.
When you think of carved stone, most people think of statues and figurines. But there are also many talented artists carving on a smaller scale for jewellery. Cameos are an excellent example of carved stones, but definitely not the only kind.
Cabochons come in a variety of shapes and sizes, and they are further classified by the dome height. Low dome, high dome, bullet and double dome.
Faceting is usually reserved for the higher quality transparent or translucent stones, though I have seen a few opaque faceted gems. The facets are designed to reflect the light in such a way that enhances the gem.
I'll go into more detail about faceted gems next post, as well as some of the ways gems are treated to enhance their appearance. Until then, happy creating!