वैमानिक शास्त्र (Vimaan Shastra-Ancient Indian Aeroplane Technology Chapter-6.3)
Select Chapter RUKMA VIMAANA "Atha Rukma Vimaana Nirnayaha" Next the principles of Rukma Vimaana. Maharshi Bharadwaaja: Bodhaananda Vritti: ☞ "Rukmascha" Sootra 1. "Rukma too" This vimaana is of golden colour. Therefore it is called Rukma vimaana, Rukma meaning gold. The Rukma should be made out of Raajaloha only. By duly processing, Raajaloha can be made to assume golden colour. That metal should be used for the vimaana. "Yaana-Bindu" says, "After first producing golden colour for Raajaloha, the vimaana should be formed." "Varna-sarvasva" mentions the colouring process: Praana-kshaara or ammonium chloride 4 parts, wild Bengal gram 32 parts, shashakanda (or lodhra?) benzoin? 18 parts, naaga or lead 20 parts, sea-foam 16 parts, maakshika or iron pyrites 6 parts, panchaanana or iron 20 parts, paara or mercury 15 parts, kshaara- traya or 3 kinds of salt: natron, salt-petre, borax, 28 parts, pancha