A diamond engagement ring can be crafted in gold or platinum. Contrary to popular belief platinum is actually softer than gold although it is heavier. Platinum will get marked a lot easier than gold. Gold is still the most popular choice because of its hardy nature; it can be easily worked with whether that is polishing, repairing or re-sizing. Gold comes in a variety of colors including white rose and yellow.  A reputable jeweler will be able to work with you no matter what your budget is for a diamond engagement ring. Their reputation will be walking out their door on your finger.