Primary Test: The beryllium diffused sapphire struck fear into the heart of the industry for several years as it was the first time that a major gemstone could be diffusion treated using a process that totally permeated the gemstone. Previous diffusion efforts with sapphire had resulted in only surface diffusion of color onto the stone. But with the advent of the Be treatment the old methods of identification went out the window. Fortunately the Be treatment imparts classic and diagnostic features that can be used to positively identify the sapphire.
The main tool is magnification. The internal characteristics left behind by the diffusion process creates inclusions that are unlike anything natural to the trained eye. These include blue halos which are the result of residual iron and titanium reforming their bond around pre-existing crystals. The re-bonding of the Fe/Ti elements causes the blue halos to be present in sapphires that otherwise are yellow, orange, and a variety of other colors. Also, the presence and formation of unusually large fingerprint type inclusions is another “tell” of the Be process.
Perhaps most important is the immersion cell. As with all diffusion treatments of gemstones the Be treatment of sapphire leaves color zoning that can be easily seen under magnification and an immersion cell. And no need to get an expensive cell, just cut the bottom of a frosted plastic Dixie cup and use tap water and you have a working immersion cell. Simply place a flashlight under it and use a 10x loupe and you have a proper immersion cell. In the immersion cell the strange color zoning patterns imparted to the stone will be quickly evident and diagnostic for Be treatment when used in conjunction with a review of the internal characteristics as outlined above.
Secondary Tests: The most important secondary test is common sense. For instance....true padparadscha sapphires are truly rare and expensive. When one finds a large padparadscha sapphire available for very low prices, or a whole parcel of pad sapphires available then common sense should tell us to be wary as the only padparadscha sapphires on the market that are cheap and plentiful are those that are Be treated. So use your common sense when shopping for sapphires as seen below. There are indeed natural stones out on the market, but they are rare and expensive. You should ask for a proper gemological verification particularly is you find the following features in sapphires you are buying or appraising.
Repair and Setting: Based on this being a true sapphire no special care is required other than would be used with a natural sapphire. Not recommended for torch heating, but cleaning in ultrasonic should not be a problem. The Be treatment has so far proven to be permanent and stable.