First big difference is the cost (price) you will usually asset that platinum jewelry is major relevant and more expensive than "white gold" jewelry items. This is rightful esteem part to the pure consistency of the platinum metal impact appendage to the preciousness of the metal itself and accountability in the manufacturing process.
This two metals are mostly used in engagement rings, and both are durable enough to withstand years of wear. But when not rhodium plated, gold white is a kind of yellowish and platinum is more grayish in color.
Next picture will show you the real differences with the metal color, discolor, durability, jewelry hardness, esteem, rarity, skin reaction and the price of White Gold and Platinum.
White gold is a lot whiter and shinier then platinum. The 14k gold is more white and is better than 18K, but if you have extra money that you can spend for really nice jewelry buy the best and top - 950 Platinum.