Appraisals - Michael is one of the most knowledgeable and credentialed appraisers in the country. Most appraisals are prepared for Insurance purposes and your jewelry appraisals should be updated every 3 to 5 years to be properly covered. There are other types of appraisals needed for different reasons such as; estate tax valuation, pre-purchase valuation, post-purchase valuation, casualty loss, dissolution of marriage (divorce), collateral, donation, bankruptcy appraisals and others.