A heat treatment method to convert deguna stones to padparadscha

As a traditional heat treatment practice, red and blue combined deguna stones are converted to pink sapphire or ruby around 1,200 degrees of Celsius under oxidizing ambient air state inside the Lakmini furnace. Under these conditions, already available red tone due to chromium (III) ions is highlighted since fading of blue colour occurs because of the dissociation of ferro - titanium bi - particle. This book introduces a novel heat treatment technique to convert pale reddish blue colour deguna stones to padparadscha sapphire by further oxidizing these dissociated Iron (II) ions into Iron (III) ions to arise yellow hue within the red tone enriched corundum host. By this heat treatment technique, pale reddish blue colour deguna stones can be successfully converted to padparadscha sapphires and golden sapphires at 1,400 degrees of Celsius under high oxidizing ambient air state inside the Lakmini furnace. Also, this heat treatment practice should be carried out placing deguna stone samples within an alumina crucible with both bottom and side ventilation holes. This book can be recommended for both novice and professional heat treatment practitioners to further escalate their skills.

Author: Thanuja Raveendrasinghe

Publisher: Scholars' Press

Publication Date: Oct 22, 2020

Number of Pages: 96 pages

Binding: Paperback or Softback

ISBN-10: 6138831489

ISBN-13: 9786138831488