Definitions for "crystallised"
If a deferred gain is crystallised it becomes chargeable to capital gains tax. A deferred gain will be crystallised if one of several defined events occur. For example a gain deferred under the enterprise investment scheme (EIS) deferral relief scheme will crystallise if you sell your EIS shares.
having become fixed and definite in form; "distinguish between crystallized and uncrystallized opinion"- Psychological Abstracts