There are several ways to obtain THCA crystals from cannabis. Ultrafast chromatography is a method used in research environments that involves filtration, rotary evaporation and purification. However, you don't need this sophisticated equipment if you want to prepare a small batch at home. Instead, you can create pure THCA crystals through a process called diamond mining.
CBD and THCA diamonds are available at several retail outlets, including licensed medical and recreational dispensaries and online retailers. Regardless of where you buy diamonds for marijuana, we recommend that you buy products that come with a Certificate of Analysis (COA) to ensure that they have been tested for potency and purity. I have personally visited an authorized hemp crop that produces high-quality flowers with high THCA content, that pass USDA pre-harvest tests and have high THCA levels (but remain within the 0.3% D9 limit) after harvest. THCA diamonds are crystal structures composed of pure THCA that result from a couple of different extraction methods, including “diamond mining” (more on that later) and the isolation of refined petroleum.
Since CBD and THC diamonds offer consumers the greatest potency of all cannabis concentrates and require a certain production method, their price may exceed that of other concentrated products. Regardless of how they're sold, diamonds will always be somewhat pure THCA products, whether they come with terpene sauce or are sold alone as isolated THCA. For example, I recently consulted a certificate of analysis (COA) of a THCA flower that showed 25% THCA and 0.18% D9. Although THCA doesn't have an intoxicating effect when ingested, the reason marijuana smokers accept this total THC profile is because THCA converts to D9 when heated in a chemical process called decarboxylation. In places where THC is legal, there is a growing market for products formulated with 99% pure THCA extract known as diamonds.