Multi-termination refers to a habit in which a columnar hexagonal crystal is terminated by multiple needle-like elements, which are often serrated. This is neither an official term, nor is the Vorobyevite Museum hung up on it, but you have to call it something.
Some have suggested that multitermination in the alkali beryl is due to the crystallization process running out of potassium ions. While the indigo color seems indicative of vorobyevite and in this piece the terminations are deep indigo throughout their crystals (including their tips) this might not suggest validity of the above-mentioned mechanism.
If you zoom in, it can be more clearly seen that in this piece many terminations are incomplete and serrated, which is typical of multiterminated Vorobyevite.
This is an example of clean termination in multiterminated Vorobyevite.
A feature often seen in multiterminated Vorobyevite is a rectangular habit, rarely seen in other beryl varieties.
Multiterminated bi-color beryl, showing that multitermination in itself isn’t unique to Vorobyevite. It’s striking how much easier vorobyevite lets itself be photographed inside a lightbox, than aquamarine.
A close-up of the aquamarine part of a bi-color beryl that shows multitermination. The terminations, however, are not as fine (needle-like) as is often the case in Vorobyevite, and less serrated.
Very difficult to capture on camera, this piece of aquamarine shows multitermination. Unlike in most multiterminated Vorobyevite the terminations are clean, flat and complete.
