Following up other question I'd like to find out if some one has created an image: a drawing or such of how the "Blood Gem" looks like? Kudos for images that have been approved or at least have an honourable mention by Trudi Canavan.
As far as I can tell, a blood gem is simply a piece of molten glass with a drop of blood embedded into it. Within the various novels they seem largely to be contained in crude gold rings or pendants (moulded into faux gems, occasionally carved). Tavaka even wears one shaped to fit directly inside a tooth cap and the one held by the leader of one of the Sachakan factions was supposedly in the shape of a wide ring:
In the Dem Ladeiri’s impressive collection of books and artifacts had been a ring, the symbol for high magic carved into the red glass “gem” in the setting. A ring that according to the Dem enabled the wearer to communicate with another magician without the conversation being overheard. Was the gem in the ring one of these blood gems?
Kariko held the shard of glass in the air. The tip slowly began to glow and melt, until a small globule had formed. This fell from the tip of the shard into Kariko’s palm...Rothen thought of the little sphere of glass. He thought back to Lord Sarrin’s briefing about the uses of black magic, and realized that Kariko had just made a blood gem.