Garnet Mineral Group: SILICATES
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Garnet
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Garnet Crystal
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![]() Almandine Garnet Markstay, Ontario CANADA |
![]() Almandine Garnet Crystal Cluster River Valley, Ontario CANADA |
Single Garnet Crystals from different locations have slightly different
appearances. Note how the garnet on the left looks rounded while the one
on the right has distinct flat planes.
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Garnet - var. Andradite Marmoraton Iron Mine, Marmoraton Township Ontario, CANADA |
![]() Andradite Garnet - Marmoraton Iron Mine, Marmoraton Township Ontario, CANADA This specimen has had the calcite removed to uncover the garnet crystals. |
Cogwheel
Garnet Crystal
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![]() SPECIMEN ORIGIN: Markstay, Ontario |
Almandine Garnets in Mica Schist
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Garnets from
Ecosource Mine, Kukagami Road, Sudbury
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Garnets from
Ambro Quarry
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Almandine Garnet in mica schist from Laniel, Quebec, CANADA ![]()
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| Almandine Garnet crystal from River Valley Occurrence, Dana Township, Sudbury District, Ontario, CANADA | |
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Garnets with Kyanite from
North Bay, Ontario, CANADA
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Garnet – the poor man’s ruby … well, some varieties may be taken for rubies when cut and polished, especially the pyropes and almandines. Usually six are listed in the garnet group, the name changing with the elements present. Garnets belong to the isometric class of crystals which may suggest cubes (correctly), but garnet crystals look more like rough balls with their twelve sides – dodecahedrons. These forms are the most common but garnet can also be found massive and sometimes light coming through a thin edge may offer a clue. But more reliable field identification help is garnet’s higher-than-you’d expect S.G. of 3.53. Despite various chemical compositions the group is very hard at 7 to 7.5 and all have glass-like conchoidal fracture. The garnet group belongs to the vast family of silicates, is widely distributed as an accessory mineral – i.e. small amounts – in many rocks but especially in strongly metamorphic types. Here are some interesting but probably not helpful tips about garnet varieties:
Garnet is widely used as a gemstone and members of our own Brampton Club have turned out some fine "gems" of garnet. But the big-time use of garnet is in the abrasives industry. A good choice too – it’s very hard, breaks with sharp edges and is common enough.
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