Moissanite (technically, Silicon Carbide) is currently protected from being cut into gem form by a patent held by Charles and Colvard in approximately 27 countries.
The US patent will be the first to expire in August, 2015, and various months in 2016 for most other countries except Mexico (2018). Note that Indian reservations within the US are exempt from US patents as they are sovereign nations, so there is no patent restriction there.
This patent covers multiple Silicon Carbide crystal types, including the one specific crystal type marketed as 'Moissanite by Charles and Colvard' (and technically known as 6H-SiC).
Note: Silicon carbide has many crystal variations (polytypes) and is a large family of crystals with over 200 members. 'Moissanite' is simply the one that is currently the easiest to grow and the first to be marketed as a gem.
Therefore, other Silicon Carbide crystal gems, such as Amora GEM which is a different member of the Silicon Carbide family, or Moissanite cut by other parties besides Charles and Colvard, cannot sell their gems into the following countries:
Silicon Carbide Gemstones – Patent protection - 2016 expiration unless otherwise noted:
Note that the patent in Korea was thrown out due to "lack of innovation" and thus customers in Korea may purchase the Amora Gem.
Until the patents in the above countries expire or are invalidated, we cannot sell any Amora H&A (Amora GEM) to customers in those countries.
Customers in the above countries can purchase our Amora enhanced Moissanite, but again, cannot purchase the Amora H&A lab gem.
US and Indian reservations: A question we have received from those who reside on Indian reservations within the US - most Indian nations are exempt from US patent law and Amora Gem can be shipped there with no restrictions. This is also for example, why gambling can be done on an Indian reservation - they are each sovereign nations within the landmass of the US. See http://www.generalpatent.com/2011/02/11/history-lesson for details.