As expected, a male amethyst ring would require a fairly large amethyst gemstone. This is probably the reason why you will notice male amethyst rings with amethyst gems that are not eye clean. However since a good quality amethyst gemstone would be modestly priced (not exactly cheap), it is a good idea to request for an eye clean gemstone to be used for your male amethyst ring.
While choosing the gemstone for an amethyst male ring, remember not to choose a very dark colored gemstone. African amethyst is considered to be the best quality but, can sometimes be very deeply colored. A male amethyst ring with a very dark colored gemstone, will not show any glitter or even lustre in the gemstone. Light penetration is very sluggish and you might not even see the transparent purple color of the gemstone.
At the same time do not go for a very pale color amethyst either, such washed out colors look dull and lifeless even in the best designs. Choose a male amethyst ring that has a moderately deep color. You should be able to see the gemstone color clearly and also get extra glare from the metal reflection around the ring. Such an amethyst male ring will look great in yellow gold or white gold.
Protection of the borders of the gemstone is a good idea for all male rings. This allows the gemstone to be firmly mounted and protects it from side impact, a positive step towards increasing the durability of the gemstone.
Make sure that the ring is strong with a good metal weight. Do not compromise on quality while checking prices. A male amethyst ring in sterling silver with a good and sturdy construction, is better than an amethyst male ring in gold that is flimsy and light weight.
Get an idea of what you should be looking for at this link: http://www.kaisilver.com/man-amethyst-ring-01-ks.htm
If you are looking for good quality amethyst rings for a lady, this link might be of interest to you: http://www.jewelry.kaijewels.com/amethyst-ring-all-kj.htm