Reconciling Fickian Diffusion Theory with Non-Fickian Diffusion Reality in Heat Treating Corundum.
In imperfect crystals such as corundum, Fickian and Arrhenius expressions fail to predict practical soak-time diffusion: theory suggests years, while defect-assisted non-Fickian transport achieves results within hours.

Oxidative Color Modification of Dark Blue Mambilla Plateau Sapphire: A Defect-Kinetic Interpretation.
Dark blue Mambilla sapphire can be lightened through controlled oxidation that selectively reduces Fe²⁺-related extinction without destabilizing Ti⁴⁺ blue chromophores. The proposed treatment uses two temperature stages governed by defect kinetics.

Oxidative Color Modification of Ruby: A Defect Kinetics Model for Reducing the Purplish Rubies
Dry-air oxidation below 1200°C reduces ruby’s purple overtone through Fe²⁺ oxidation and hydroxyl removal, while chromium remains stable and preserves red saturation. The treatment improves brightness without altering the primary chromophore.

Quasi-Isochoric Reduction in Sapphire Heating— Conceptual Framework and Practical Furnace Configuration
Sapphire reduction heating under quasi-isochoric conditions relies on confined furnace geometry that concentrates reactive gases near the sample and stabilizes lattice-level reduction pathways. Standard open furnaces cannot reproduce the same localized reaction environment.

Defect Corridor along the Compensated Furnace Trajectory (CFT) in Sapphire Heat Treatment
Sapphire reduction heating under quasi-isochoric conditions relies on confined furnace geometry that concentrates reactive gases near the sample and stabilizes lattice-level reduction pathways. Standard open furnaces cannot reproduce the same localized reaction environment.

Compensated Furnace Trajectory Normalization for Redox Control in LPG–O2 Combustion Sapphire Heat Treatment
Furnace trajectory normalization converts LPG–O₂ combustion behavior into a practical redox coordinate that allows reproducible sapphire heating within a controlled thermochemical corridor.

BLUE SAPPHIRE BLUEPRINT: The Etiology of Mechanical and Atmospheric Failure: A Thermodynamic and Engineering Analysis in Gas-Oxy Combustion Furnaces
Stable blue sapphire coloration depends on maintaining LPG–O₂ combustion within a narrow thermodynamic corridor where Fe²⁺–Ti⁴⁺ defect states remain stable. Mechanical drift, fuel variability, and furnace asymmetry are the main causes of treatment failure.

by Ted Themelis
Total 7 monographis+slipcase
530 pp. full color
Over 1010 color photos
Price:USD350 postpaid
Published: June 2025

These monographs are written based on the fundamental structure of the previous editions of The Heat Treatment of Ruby- Sapphire, written and published by the same author in 1992, 2012, and 2019. This newest edition (June .2025) is presented in the form of monographs, aiming to provide the tools for understanding the heat treatment of ruby-sapphire, learning how to think alternatively, and producing new ideas that will ultimately formulate new models and exciting new inspirations.

MONO No.1. An intrroduction to the Heat Treatment of Ruby-Sapphire
MONO No.2. First Principles in Heating Ruby-Sapphire
MONO No.3. The Effect of Heat on Attributes of Ruby-Sapphire
MONO No.4. The Effect on Inclusions of Ruby-Sapphire
MONO No.5. Heat Treatment Parameters of Ruby-Sapphire
MONO No.6. Methodology of Heat Treating Ruby-Sapphire
MONO No.7. Equipment for Heat Treating Ruby-Sapphire

V80-1200