Glass gems are dome-shaped lumps of glass with flat bottoms that can be used as tesserae (tile) in craft projects and mixed-media mosaic.
These glass gem are American made by Marble King and have more intense colors and better clarity than most Asian gems.
The glass gems are sold by the half pound.
The count of 60+ gems is a NOMINAL count only,
which means the bags can contain less than 60 pieces when they are running large.
The gems are APPROXIMATELY 5/8" in diameter.
They are NOT perfectly circular. Note that "TUMBLED" gems have a FROSTED surface.
Read more about using glass gems in mosaics at the bottom of this page.
Glass Gems Used As Mosaic Tile
You can find cheaper glass gems on the market, but those are made in China. Our gems are made in America in accordance with more sustainable labor and environmental standards, and that is what you are paying for. Buying American-made products has nothing to do with nationalism and everything to do with being a responsible global citizen.
These gems are circular domes of glass, but they vary in size and exact shape. Please do NOT purchase these if you need tightly controlled shapes or sizes. Also, the glass is not optical quality and contains occasional bubbles. We sell these for use as mosaic tile, not covers for photo refrigerator magnets, etc.
A 1/2-pound bag of glass gems coveres approximately 25 square inches, possibly as much as 36 square inches or 1/4 square foot. Glass gems are better used as accents than area coverage because they are circular and can nest together only so tightly. There will always be a larger than desired gap at the juncture between multiple gems.
Glass gems are thicker than most types of glass mosaic tile, which is usually ~1/8 inch thick. The glass gems are about ~3/16 inch thick, but that is approximate and not tightly controlled. All that being said, the reason to use something like glass gems is precisely BECAUSE you want something that sticks out slightly above the surface of the ordinary tile. This gives the otherwise flat surface of the mosaic an element of dimensionality, something that can be felt with the hand.
Cutting glass gems leaves a sharp edge on an otherwise rounded shape, and for this reason it isn't commonly done. The sharp edge can be smoothed using the fine side of a marble file, but that only removes the safety issue. Visually, the cut edge will still be sharp compared to the other part of the gem. If you do need to cut the gem, use a mosaic glass cutter.
- American-made glass gems.
- APPROXIMATELY 5/8" inch diameter.
- dome-shaped circular lumps with flat bottoms.
- varies in size and circularity.
- 1/2 pound.
- approximately 60+ pieces. Piece count is lower when gems are running larger, and this varies by manufacturer batch.
Use In Mosaic Art
The tops of the glass gems are dome shaped instead of flat surfaces, and this has significant implications for the grouting process. When grouting a mosaic made from glass gems, many novices fail to remove enough grout, leaving most of the glass gem covered. The result is that the finished mosaic appears to be mostly grout with just a little bit of glass peeking out. You have to use your fingertips to remove the grout covering the edges of the gems and make sure that you expose more than just the very tops of the domes.
For more information on how to design mosaics and use glass gems to create artwork, see our page of Frequently Asked Questions
or our List of How-To-Mosaic Pages, which are topic specific.
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